The suggested answer is A, C.
SRV records used for SIP and H.323 communications need to follow specific naming conventions. For SIP over a secure connection, the appropriate SRV record typically follows the format _sips._tcp.example.com, ensuring encrypted communication over TCP. For H.323, which facilitates video conferencing and VoIP, the SRV record _h323ls._udp.example.com is used for UDP location signaling, crucial for discovering and managing endpoints. Hence, these two options are valid and align with standard conventions for their respective communication protocols.