Refer to the exhibit.

A user is going through a series of dialing steps on a SIP Type A 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 not associated with any SIP dial rules.
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.
The SIP IP phone waits for the inter-digit timer expiry or for the Dial soft key to be selected before
it sends all digits to the Cisco Unified Communications Manager in a SIP INVITE message.

D.
The SIP IP phone waits for the inter-digit timer expiry, or for the Dial soft key to be selected
before it sends the first digit in a SIP INVITE and the subsequent digits in SIP NOTIFY messages.

E.
The SIP IP phone sends all digits to the Cisco Unified Communications Manager in a SIP INVITE
message as soon as the fourth digit is pressed.

Explanation:
Because Type A SIP phone with no SIP dial rules sends digit in Enbloc style.All digits are sent to
CUCM after the user completes the dialing and press the Dial softkey.
https://supportforums.cisco.com/document/87236/working-concept-sccp-sip-phonesand-dial-rules.