A user has reported that keys pressed when accessing Cisco Unity Express are not being
acknowledged by the system. This configuration is found on the voice-enabled IOS router:
Which configuration command is needed to complete the configuration and solve the
problem?

A.
dtmf-relay sip-notify

B.
dtmf-relay rtp-nte

C.
dtmf-relay cisco-rtp

D.
dtmf-relay h245-signal