Summary:
The concern is about the quality and reliability of the custom Apex sharing logic. Since Apex runs in system context and bypasses sharing, a coding error could grant access to the wrong users. The primary mitigation for this risk is rigorous, automated testing that verifies the sharing logic behaves as expected under different user contexts and data scenarios before being deployed to production.

Correct Option:

B. Use runAs system method in test classes to test using different users and profiles.
This is the correct and most critical recommendation. The runAs method in an Apex test class allows the developer to simulate the code executing as a specific user with a specific profile and permission set. By writing comprehensive tests that use runAs for both users who should and should not get access, the IT team can automatically validate that the Apex sharing logic is correct and does not grant improper access, ensuring its reliability.

Incorrect Options:

A. Use isShareable keyword in Apex classes to assure record visibility will be followed.
The isShareable keyword in a SOQL query is used to return sharing information about why a user has access to a record. It is a diagnostic tool, not a preventative one. It does not enforce or validate that the correct sharing is in place; it only explains existing sharing.

C. Use isAccessible keyword in Apex classes to assure record visibility will be followed.
The correct method is isAccessible(), but it is used to check a user's Field-Level Security (FLS) or object-level read permission before querying or displaying that data. It is unrelated to enforcing or testing the record-level sharing rules created by Apex managed sharing. It does not mitigate the risk of incorrect record access.

Reference:
Salesforce Help: Using the runAs Method

Summary:
This question focuses on performance optimization for major metadata operations in a large, complex Salesforce org. A large-scale realignment of the Role Hierarchy is a massive, system-intensive task that involves recalculating sharing access for a significant portion of the organization's data. Without the proper tool, this operation can lead to performance degradation and locking issues, preventing other users from saving records.

Correct Option:

A. Granular Locking:
This is the correct advanced tool. Granular Locking is a performance feature that Salesforce can enable for specific, high-impact operations like massive role hierarchy changes, ownership transfers, and territory realignments. Instead of locking large sets of data, it processes the sharing recalculations in smaller, more manageable chunks. This prevents system-wide performance issues and record-locking errors, allowing the realignment to proceed without disrupting business operations.

Incorrect Options:

B. Skinny Table Indexing:
This is a performance feature for data retrieval, not metadata operations. Skinny tables are custom database tables that consolidate frequently accessed fields from a standard object and its related parent objects to speed up SOQL queries. They have no function in optimizing the process of recalculating sharing due to a role hierarchy change.

C. Partitioning by Divisions:
Divisions are a data segmentation feature used to filter records in lists, reports, and search results. They are a way to categorize data, not a performance tool. Divisions do not impact the performance or locking behavior of sharing recalculations triggered by changes to the role hierarchy.

Reference:
Salesforce Help: Granular Locking for Role and Territory Realignments

Summary:
The requirement is to restrict the visibility of a specific field (VIP Flag) on the Contact object to only users with the "Private Banking Rep" profile. This is a classic field-level security (FLS) requirement. The solution must control whether the field is rendered on the page at all for a given user, which is a function of the user's profile and permission sets, not the page layout.

Correct Option:

C. Set the Field Level Security for the VIP Flag field so that it is visible to Private Banking Rep Profile.
This is the correct and foundational approach. Field-Level Security in the profile is the primary gatekeeper that determines if a field is visible, readable, or editable. By setting the FLS for the VIP Flag field to "Visible" only for the Private Banking Rep profile and "Not Visible" for all other profiles, the field will be hidden from users who should not see it, regardless of the page layout they are assigned.

Incorrect Options:

A. Change the type of VIP Flag field to a picklist, define a new record type for the Contact Object and make the picklist field available for Editing.
This is an overly complex and incorrect solution. Record types control which fields are available on a page layout for a specific category of records, not which users can see a field. A user with a profile that has FLS access to the field could still see it on a different record's layout or via the API. It does not securely hide the field based on user role.

B. Define a page layout for Contact Object and add the VIP Flag field for that layout.
Remove the VIP Flag field from other layouts. This is insecure and incorrect. Page layouts only organize fields that a user already has permission to see via their profile. If a user's profile has FLS granting them visibility to the VIP Flag field, they can still access it via reports, the API, or by switching to a different layout (if available), making this an unreliable method for enforcing security.

Reference:
Salesforce Help: Field-Level Security

Summary:
The requirement is to segment data access between two sales teams based on the type of Account (Person vs. Business) in an org with a Private Organization-Wide Default (OWD). The solution must automatically grant the retail sales team access to all Person Accounts, regardless of ownership, while continuing to restrict their access to Business Accounts. This requires a record-level sharing mechanism that distinguishes between the two account types.

Correct Option:

A. Create a criteria-based sharing rule giving the Retail Sales role access to Accounts of type PersonAccount.
This is the correct solution. A criteria-based sharing rule can use the isPersonAccount field as a filter to identify all Person Account records. This rule can then be configured to share those records with the Retail Sales role (and its subordinates). This automatically grants the required access to all retail customers without giving access to commercial ones.

Incorrect Options:

B. Create an owner-based sharing rule on AccountContactRelation to grant access to all account contact roles records owned by retail sales reps.
This is incorrect for several reasons. First, it focuses on the AccountContactRelation object, not the Account object itself. Second, an owner-based rule would only share records owned by the retail sales reps. The requirement is for them to see all retail customers, even those owned by other users (e.g., created by a call center). This solution fails to meet the core requirement.

C. Update the Retail Sales profile to grant access to Person Account record type.
This is incorrect because profiles control object-level permissions and record type assignment, not record-level access. Granting access to a record type allows a user to create records of that type, but with a Private OWD, they would still only be able to see the Person Accounts they own. It does not grant visibility to all Person Accounts in the org.

Reference:
Salesforce Help: Sharing Rules

Summary:
Apex code runs in system context by default, meaning it bypasses all user-level Field-Level Security (FLS) and object permissions. The custom class is updating fields that some users are not permitted to edit. The solution must enforce FLS checks within the Apex code itself to respect the user's profile and permission set settings, ensuring the code does not perform updates the current user is not authorized to make.

Correct Option:

C. Use the IsUpdateable() Apex method to test each field prior to allowing update.
This is the correct and most precise solution. Before updating a field in the Apex class, the code should call Schema.SObjectType.Opportunity.fields.MyField__c.isUpdateable() to check if the current user has permission to edit that specific field. If the method returns false, the code should skip updating that field. This programmatically enforces FLS within the system context.

Incorrect Options:

A. Add the With Sharing keyword to the class.
This keyword enforces record-level sharing rules (e.g., which opportunities the user can see), but it does not enforce field-level security. A class declared with sharing running in system context will still bypass FLS and can update read-only fields.

B. Put the code in an inner class that uses the With Sharing keyword.
This is incorrect for the same reason as option A. Nesting the code in an inner class with with sharing only affects record visibility for SOQL queries. It has no impact on the enforcement of field-level permissions for DML operations. The FLS check must be explicit.

Reference:
Salesforce Apex Developer Guide: Enforcing Field-Level Security