A. After two consecutive missed keep-alive packets, Switch-1 disables interface 1, and the interface stays disabled until the issue is fixed.

B. Switch-1 disables interface 1 for 10 seconds, and then re-enables it. The same process repeats twice.
If the issue persists, the switch disables the interface permanently.

C. Switch-1 disables interface 1 for 10 seconds and then re-enables it. The interface continues to be re- enabled and disabled every 10 seconds until the issue is fixed.

D. After two consecutive missed keep-alive packets, Switch-1 sends SNMP traps, and Link 1 stays up until the issue is fixed.