Which statement about how digits are forwarded to the Cisco Unified Communications Manager for further call processing is true?

Refer to the exhibit.

A user is going through a series of dialing steps on a SIP Type B IP phone to call a SCCP IP phone. Both phones are registered to the same Cisco Unified Communications Manager cluster. Assume that the calling SIP phone is associated with a SIP dial rule with a pattern value of "2001".

Which statement about how digits are forwarded to the Cisco Unified Communications Manager for further call processing is true?
A . As each digit is pressed on the SIP IP phone, it is sent to the Cisco Unified Communications Manager in a SIP NOTIFY message as a KPML event.
B . The SIP IP phone waits for the inter-digit timer expiry and then sends each digit to the Cisco Unified Communications Manager as a separate KPML event in a SIP NOTIFY message.
C . As soon as the user selects the Dial soft key, the SIP IP phone forwards all digits to the Cisco Unified Communications Manager in a SIP INVITE message.
D . As soon as the Dial soft key is selected, the SIP IP phone forwards the first digit in a SIP INVITE and the subsequent digits in SIP INFORMATION messages.
E . The SIP IP phone waits for the inter-digit timer expiry, and then sends all digits to the Cisco Unified Communications Manager in a SIP INVITE message.

View Answer

Answer: C

Explanation:

Reference: https://supportforums.cisco.com/document/87236/working-concept-sccp-sip-phones-and-dial-rules.