For which use case do you create a new rule in a Pega Platform™ application?

For which use case do you create a new rule in a Pega Platform™ application?
A . A developer creates a parallel process to audit changes that a service agent makes.
B . A developer makes changes to an email message configured in the case life cycle.
C . A designer reuses a UI section every time the same behavior is needed in the application.
D . A business user issues a change request for the application to set the default value of a field.

Answer: D