Which two statements explain the operation of BFD asynchronous mode?

C (Both modes use control packets):Regardless of whether echo packets are used, BFD asynchronous mode always relies on periodic transmission of control packets to verify session liveliness.

E (Echo mode uses separate packets):When echo is enabled, the echo packets are transmitted in addition to control packets, providing even faster failure detection by relying on data plane processing.

Other options explained:

A: Control and echo packets are never combined into a single packet.

B: Both modes always use control packets; echo packets are optional.

D: BFD echo packets are locally looped, not reflected back from the remote device.