Summary:
This question tests the relationship between Chatter file sharing and the underlying record-level security of the object it is posted to. When a file is attached to a Chatter feed on a record, its visibility is not independent; it inherits the sharing model of the parent record. The file's access control is dynamically determined by who has access to the record itself.

Correct Option:

C. The user who posted the file and users with access to the record.
This is the correct and fundamental principle. The file's visibility is governed by the "Content on Records" sharing model. Since the object's Organization-Wide Default (OWD) is Private, only the record owner and users who have been explicitly granted access to that specific record (via role hierarchy, sharing rules, teams, etc.) can see the record and, by extension, the file posted on its feed.

Incorrect Options:

A. The user who posted the file and users with a shared Chatter post link to the file.
This is incorrect. While sharing a direct link to a Chatter post can sometimes grant access, this is a secondary, "link-based" sharing mechanism. The primary security is still derived from the record. If a user without record access receives the link, they will be blocked from viewing the file and the post.

B. Only the user who posted the file.
This is incorrect because it ignores the record's sharing model. If the user who posted the file is not the record owner, but has access to it via a sharing rule, they can see it. Conversely, other users (like the record owner or users in the same role) who have access to the record will also be able to see the file, not just the user who posted it.

Reference:
Salesforce Help: How Files Are Shared

Summary:
The core requirement is to securely share large files externally with customers, with the specific security mandate that each shared link must be protected by a password. The solution must be native to the Salesforce Platform to avoid third-party dependencies and must enforce password protection at the individual link level, not just at a general site access level.

Correct Option:

B. Create a content delivery; during creation, the user should select the option to require a password to access content.
This is the correct native Salesforce solution. A Content Delivery creates a secure, time-limited, and downloadable link for a file. During its setup, the user can explicitly enable the "Require password to access content" option. This mandates that anyone clicking the link must enter a password set by the sales rep, perfectly fulfilling the CISO's requirement.

Incorrect Options:

A. Utilize an AppExchange product for delivering password protected files to customers.
While an AppExchange solution might exist, the question implies a desire for a native Salesforce capability. Recommending a third-party tool is unnecessary when Salesforce Files (Content Deliveries) has this functionality built-in, making it a less optimal and potentially more costly answer.

C. Set up an Experience Cloud site for customers to access files and share the file with customers via Chatter.
Customers can then log in to the site to access the content. This solution provides access control via login credentials but does not meet the specific requirement for password-protected file links. The security is applied at the site level, not per file link. A Chatter post with a file would grant access to anyone with site access, not a unique password per shared file.

Reference:
Salesforce Help: Create a Content Delivery

Summary:
The requirement is to store a highly sensitive encryption key within Salesforce for use by Apex code while ensuring it is completely hidden from all users, including those with the "View Setup and Configuration" permission. Standard custom settings or metadata are visible to users with this permission. The solution must use a feature that enforces true secrecy, even from administrators viewing the setup interface.

Correct Option:

C. Create a protected custom metadata type that stores the encryption key.
Package the protected custom metadata type with its associated records in a managed package. Install the package in the production org. This is the only correct solution. A Protected Custom Metadata Type is a special type whose field values are encrypted and accessible only by Apex code that resides in the same managed package. Once installed, the key's value is hidden from the UI, the API, and all users, including system administrators. It is the most secure way to store secrets within Salesforce.

Incorrect Options:

A. Create a custom metadata type that stores the encryption key.
Make sure that only the admin profile has access to the custom metadata type so that end users cannot access the encryption key. This is incorrect because a standard (non-protected) Custom Metadata Type is not hidden. Any user with the "View Setup and Configuration" permission can see its records and field values through the Setup menu, regardless of profile or permission set assignments. It does not provide the required confidentiality.

B. Create a protected custom metadata type that stores the encryption key.
Package the protected custom metadata type with its associated records in an unlocked package. Install the package in the production org. This is incorrect because Protected Custom Metadata Types are only supported in Managed Packages. An Unlocked Package does not provide the container necessary to enforce the protection and secrecy of the metadata's values. The key would still be exposed.

Reference:
Salesforce Help: Protected Custom Metadata Types

Summary:
This question tests the understanding of folder sharing, specifically the "Private Reports" folder. This is a special, user-specific folder that is not shared by default. The security of a report is a combination of the user's data visibility (what records they can see) and the folder's visibility (who can see the report definition itself). For a report saved in a "Private Reports" folder, the folder's restrictive sharing is the determining factor.

Correct Option:

A. The report owner.
This is correct. The "Private Reports" folder is unique to each user and is, by its nature, private. Reports saved in this folder are only accessible to the user who created and saved them. No other users, including system administrators (unless they log in as that user), can view or run a report stored in another user's "Private Reports" folder.

Incorrect Options:

B. The report owner and any users who have been given access to the “My Private Reports” folder.
This is incorrect because the "Private Reports" folder cannot be shared. Unlike public folders or other private folders, there is no mechanism to grant access to another user's "Private Reports" folder. It is strictly personal.

C. The report owner and users with the View All Data permission.
This is incorrect. While users with the "View All Data" permission can see all records in the organization, they cannot see the report definition itself if it is stored in a private folder they do not have access to. The "View All Data" permission overrides object-level and field-level security but does not override folder-level sharing.

Reference:
Salesforce Help: Grant Access to Folders

Summary:
A custom Apex class powering a Lightning component runs in system context by default, bypassing all user-level security checks. This causes two distinct security breaches: 1) It returns all Shipment records queried, ignoring sharing rules (record-level security), and 2) It exposes the Shipment Amount field to users whose Field-Level Security (FLS) should hide it. The Apex code must be made aware of and enforce the current user's permissions.

Correct Option:

B. Use isAccessible() method in Apex classes to check field accessibility.
This is the correct feature for enforcing field-level security (FLS). To prevent sales reps from seeing the Shipment Amount, the Apex code should use Schema.SObjectType.Shipment__c.fields.Amount__c.isAccessible() before including that field in the query or displaying its value. This ensures the user's FLS is respected. For record-level security, the class should use the WITH SECURITY_ENFORCED clause or the Security.stripInaccessible method.

Incorrect Options:

A. Use isShareable keyword in Apex classes to assure record visibility.
The isShareable keyword is used in Apex to force a query to return sharing information (i.e., why a user has access). It does not enforce sharing rules; it merely explains them. It does not prevent users from seeing records they shouldn't and does nothing for field-level security.

C. Use runAs in test class to enforce user permissions and field level permissions.
The runAs method is used within test classes to simulate running code as a specific user to verify that security is working correctly. It is a testing feature, not a runtime security feature. Using it in a test class would have helped catch these problems during development but is not the feature missing from the main application code that is causing the production issue.

Reference:
Salesforce Help: Enforcing Object and Field Permissions