Which role does Call Policy play when preventing toll fraud on Expressways?

Which role does Call Policy play when preventing toll fraud on Expressways?
A . It controls which calls are allowed, which calls are rejected, and which calls are redirected to a different destination.
B . It changes the calling and called number on a call.
C . It changes the audio protocol used by a call through Expressways.
D . It changes the audio codec used in a call through Expressways.

Answer: A