A company notices that their unit tests in a test class with many methods to create many records for prerequisite reference data are slow. What can a developer to do address the issue?

A company represents their customers as Accounts that have an External ID field called Customer_Number__c. They have a custom Order (Order__c) object, with a Lookup to Account, to represent Orders that are placed in their external order management system (OMS). When an order is fulfilled in the OMS, a REST call to Salesforce should be made that creates an Order record in Salesforce and retates it to the proper Account. What is the optimal way to implement this?

Assuming the CreateOneAccount class creates one account and implements the Queuetable interface, which syntax tests the Apex code?
A)

B)

C)

D)

What should be added to the setup, in the location indicated, for the unit test above to create the controller extension for the test?
A)

B)

C)

D)

A lead developer for a Salesforce organization needs to develop a page-centric application that allows the user to interact with multiple objects related to a Contact The application needs to implement a third-party JavaScript framework such as Angular, and must be made available in both Classic and Lightning Experience.
Given these requirements, what is the recommended solution to develop the application?