Which command should you use to configure a dial peer to support T.38 fax relay and to use Cisco fax relay if T.38 negotiation is unsuccessful?

Which command should you use to configure a dial peer to support T.38 fax relay and to use
Cisco fax relay if T.38 negotiation is unsuccessful?

A.
fax protocol t38 fallback cisco

B.
fax t38 fallback cisco

C.
fax relay t38 cisco

D.
fax relay t38 backup ciscorelay

Explanation: