The valid SOQL query on a Big Object must match the indexed fields exactly. Since Account__c, Program__c, and Transaction_Date__c are the indexed fields, the SOQL query must specify those fields exactly in the WHERE clause, including exact match conditions (no LIKE or INCLUDES).

A hierarchy custom setting can be used to create a configuration that the trigger checks before executing its logic. This allows admins to set the configuration to bypass the trigger logic when loading data, without changing the trigger itself or impacting other users.

The correct code to fire the event when the search has completed in a Lightning component is option B. $A.get("e.c.searchComplete") is the syntax used to get the event, setParams is used to set the parameters, and fire is used to dispatch the event.

Jest tests are essential for developing Lightning Web Components (LWC) because they allow developers to ensure the quality and correctness of their components in isolation from the rest of the application. Reason A is incorrect because testing non-public properties breaks encapsulation and is considered bad practice. B is correct because Jest tests can simulate user interactions with the component, such as clicking buttons or entering text, to ensure it behaves as expected. C is correct as well because Jest tests can confirm that the component renders the expected DOM output, which is crucial for ensuring that the HTML structure of the component is accurate. D is not the best choice since Jest is more suited for testing components in isolation rather than how multiple components interact; integration tests are more appropriate for that. Lastly, E is correct because Jest tests can verify that events are fired at the appropriate times, which is a critical part of the component's interaction with the rest of the application.
Reference
Jest Testing: Lightning Web Components Testing
Jest Testing Best Practices: Lightning Web Components Jest Best Practices

To determine which objects to include in the response, the developer should check the isCustom() value on the sObject describe result. This method returns a Boolean indicating whether the sObject is a custom object.