Explanation:

To name a Lightning web component’s folder and associated files, the developer should follow these naming rules:

Must begin with a lowercase letter
Must contain only alphanumeric or underscore characters
Must be unique in the namespace
Can’t include whitespace
Can’t end with an underscore
Can’t contain two consecutive underscores
Can’t contain a hyphen (dash)

The only exception to the last rule is when separating the namespace from the component name in markup. For example, if the component is in the example namespace and has the name myComponent, the folder name should be myComponent, but the markup tag should be . The hyphen character (-) is required by the HTML standard for custom element names. The other options are either invalid or not recommended. For example, including whitespace or using consecutive underscores will cause errors, and using a single underscore will look odd and may confuse developers consuming the component.

References: B2B Commerce and D2C Commerce Developer Guide, Lightning Web Components Developer Guide

Explanation:

To implement a custom child checkout component for a B2B or B2C store created with an LWR template, the developer must implement the CheckoutStep interface from the commerce/checkout module. This interface defines the methods and properties that the child component must have to communicate with the parent checkout component and the checkout data provider. The CheckoutStep interface extends the UseCheckoutComponent interface, which provides the common functionality for all checkout components, such as loading and saving data, reporting validity, and handling errors.

Explanation:

The correct answer is External Objects. External objects are similar to custom objects, except that they map to data that’s stored outside your Salesforce org12. You can use external objects to access data in real time via web service callouts, without copying the data into your org12. External objects are read-only by default, but you can enable write operations for some data sources12.

Big Objects are not the correct answer. Big objects allow you to store and manage massive amounts of data on the Salesforce platform. However, big objects are not suitable for referencing historical data in another system, as they require importing the data into the org and incur storage costs.

Lightning Out is not the correct answer. Lightning Out is a feature that lets you run Lightning components in any container outside the Salesforce platform. However, Lightning Out does not provide a way to reference historical data in another system, as it is mainly used for embedding Lightning components in other web pages or apps.

External SOQL queries in Apex code are not the correct answer. External SOQL queries are a way to query data from external data sources using SOQL syntax in Apex code. However, external SOQL queries require defining an external data source and an external object first, so they are not a product feature by themselves, but rather a way to use external objects in Apex code.

References:

B2B Commerce on Lightning Experience Developer Guide
B2B Commerce and D2C Commerce Developer Guide
Salesforce Accredited B2B Commerce Developer
Work with External Data Sources
Access External Data With Salesforce Connect
Migrate data from one organization to another
Monitor Login History
[Big Objects]
[Lightning Out]
[External SOQL Queries]

Explanation:

For maintainable and scalable Lightning Web Component development, it's recommended to style components by targeting the :host pseudo-element in the component's CSS file and by applying Salesforce Lightning Design System (SLDS) classes to internal elements. These practices ensure consistent styling that aligns with Salesforce's design standards and provides a clear separation of concerns between component structure and styling.

Explanation:

To bring some historical data into an org, the data must reside in the org, but cannot be populated in standard or custom objects, and the customer is fine with developers building UI components to surface this data on a case-by-case basis, the option that allows a developer to meet all of these requirements is big objects. Big objects are a type of object that can store and manage massive amounts of data on the Salesforce platform. Big objects can store up to billions of records and are accessible through a subset of SOQL or custom user interfaces. Big objects are not subject to the same storage limits or performance issues as standard or custom objects and are suitable for storing historical or archived data that does not need to be updated frequently. Big objects can be defined using Metadata API or declaratively in Setup. Lightning Canvas is not an option that allows a developer to meet all of these requirements, as it is a framework that allows developers to integrate third-party applications into Salesforce. Lightning Canvas does not store data in the org, but rather displays data from external sources using an iframe. External objects are not an option either, as they are a type of object that map to data stored outside Salesforce. External objects do not store data in the org, but rather access data from external systems using OData services. Lightning Out is not an option either, as it is a feature that allows developers to use Lightning components outside Salesforce.

Lightning Out does not store data in the org, but rather renders components on external web pages or applications.

Salesforce References: Salesforce Help: Define BigObjects, Salesforce Help: Lightning Canvas Developer’s Guide, Salesforce Help: External Objects, Salesforce Developer Blog: Lightning Out