Which one of the following description about ICMP is CORRECT?

Question $5$ options:

In an ICMP redirect attack, attackers sent out ICMP Echo to the victims.

The ICMP protocol is at the transport layer of the network protocol stack, the same layer as TCP$.$

In an ICMP Smurf attack, attackers send ICMP packets with real IP addresses so that the destinations will respond to the attack sources.

Network administrators often block incoming and outgoing ICMP on network devices to prevent the protocol being abused by attackers.