What method can be used to send DTMF tones?
A . UPDATE
B . C INFO
C . C MESSAGE
D . C NOTIFY
E . C OPTIONS
Answer: E
Explanation:
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/sip/configuration/124t/sip-12-4t-book/voi-sip-dtmf.html