Referring to the exhibit, users are reporting that their FortiFones ring but when they pick up, the cannot hear each other. The FortiFones use SIP to communicate with the SIP Proxy Server and RTP between the phones.
Which configuration change will resolve the problem?
A)

B)

C)

D)

http://docs.fortinet.com/uploaded/files/2813/fortigate-sip-54.pdf

A.
Option A

B.
Option B

C.
Option C

D.
Option D