Which two statements explain the operation of BFD asynchronous mode? (Choose two.)

BFD with echo does not use fully independent, parallel streams of control and echo packets - the echo function reduces the frequency of control packets rather than running a completely separate control packet channel alongside echo packets.

Both BFD asynchronous mode with echo packets and without echo packets fundamentally rely on control packets for session establishment and maintenance, making control packets common to both operational modes.

BFD asynchronous mode with echo packets integrates the forwarding-path verification into the echo packet stream while still leveraging control packets, effectively combining the roles so that a single packet flow tests the complete path.

Without echo, BFD control packets are exchanged between both endpoints; the originating router does not simply receive its own packets back - that loopback behavior is specific to the echo function.

This answer is incomplete as presented and does not accurately distinguish the operational difference between the two modes in a technically precise way.