While an external caller is trying to leave a voicemail on a company system, they are cut off after 30 seconds. Which administrator action resolved this issue?
A. Add the no mgcp timer receive-rtcp command.
B. Add the mgcp timer receive-rtcp 60 seconds command.
C. The default time is 30 seconds and it cannot be changed.
D. Add the mgcp timer add 30 seconds receive-rtcp command.