Which of the following statements about smurf is true?

The smurf attack uses ICMP echo requests, not UDP; a UDP-based spoofing and flooding variant is known as the fraggle attack, which is a distinct attack type.

A smurf attack sends ICMP echo request packets with the victim's spoofed source IP to a subnet's broadcast address, causing every host on that network to send an ICMP echo reply back to the victim. The combination of IP address spoofing and ICMP broadcast flooding creates a significant traffic amplification effect that overwhelms the victim's network resources.

Sending IP fragments that cannot be reassembled by the target is the defining characteristic of the Teardrop attack, not the smurf attack.

Leaving TCP ports open in a half-open state is associated with a SYN flood attack; the smurf attack is ICMP-based and does not involve TCP port state manipulation.