The system method, ___________, lets you write test methods that change user contexts to either an e

The system method, ___________, lets you write test methods that change user contexts to either
an existing user or a new user.

A.
System.testAs()

B.
System.testAsUser

C.
System.runAsUser()

D.
System.impersonateUser()

E.
System.runAs()

F.
None of these