Explanation: The correct answer is D because it uses the StandardSetController class, which provides built-in pagination support for Visualforce pages. The StandardSetController can be initialized with a list of sObjects, a SOQL statement, or the ID of a filter. It also provides methods to navigate through the pages of data, such as first(), last(), next(), and previous(). By using the StandardSetController, the developer can avoid hitting the view state limit, which is 135 KB for Visualforce pages. The view state is the amount of data that is persisted between page requests. It includes the component tree, component attributes, and controller state. The StandardSetController reduces the view state size by storing only the current page of data in the view state, and not the entire data set.
The other options are incorrect because they do not provide an efficient or reliable way to implement pagination for Visualforce pages. Option A uses lazy loading and a transient list variable, which are not recommended for pagination. Lazy loading is a technique that defers loading data until it is needed, which can improve the initial page load time, but it can also cause performance issues if the data set is large or complex. A transient list variable is a variable that is not stored in the view state, which can reduce the view state size, but it can also cause data loss or inconsistency if the page is refreshed or redirected. Option B uses JavaScript remoting with SOQL offset, which is not a good practice for pagination. JavaScript remoting is a technique that allows Visualforce pages to communicate with Apex controllers using asynchronous JavaScript calls. SOQL offset is a clause that allows skipping a specified number of rows in a query result. However, JavaScript remoting has some limitations, such as the maximum size of the response payload (15 MB) and the maximum number of remoting calls per page (10). SOQL offset also has some limitations, such as the maximum offset value (2,000) and the performance impact of skipping many rows. Option C implements pagination with an OffsetController, which is a custom controller that uses the SOQL offset clause to paginate the data. This option has the same drawbacks as option B, as it relies on the SOQL offset clause, which is not a scalable or performant solution for pagination. References:
- Trailhead: Pagination with a StandardSetController
- Trailhead: Visualforce View State
- Salesforce Developer Guide: StandardSetController Class
- [Salesforce Developer Guide: JavaScript Remoting for Visualforce]
- [Salesforce Developer Guide: SOQL OFFSET Clause]