ping -a X-c Y-s z -vpn-instance M 10.5.16.2, what is the meaning of this command? (Multiple choice)

Ethernet is a network that supports broadcasting. Once there is a loop in the network, this simple broadcasting mechanism will cause catastrophic consequences.
Which of the following phenomena may be caused by loops? (Multiple choice)

BFDLink state detection at the heart (millisecond) level can be achieved.

In OSPFv3, the LSA whose propagation range is an area has () types. (Fill in Arabic teaching characters only)

According to this picture, the door can be judged?