An engineer receives a ticket to troubleshoot a one-way audio issue with these symptoms: User A can hear user and vice versa. User A can hear user C, however user cannot hear user A. User can heat user C, however user cannot hear user . Which two properties are the most likely reasons for this issue? (Choose two.)
A. The Cisco EX60 default gateway of user is missing from the network configuration.
B. The NAT device is allowing only RTP/RTCP ports from the internal network to the DMZ.
C. The Cisco EX60 of user is not responding to requests coming from the TMS server.
D. The Cisco VCS Expressway is not responding to the SIP INVITE coming from the Cisco VCS Control.
E. The router does not have a route back from the DMZ to the internal network.