Refer to the exhibit.
Which description of a User Agent Server that sends this message is true?
A. The UAS sends this message in response to an earlier PRACK received
B. The UAS sends this message in response to an earlier INVITE that contains PRACK
C. The UAS sends this message in response to an earlier ACK received
D. It is not possible for the UAS to send this message
E. The UAS sends this message in response to an earlier INVITE received
Correct