You are examining a packet capture session in Wire shark and see the packet shown in the accompanying image. Based on what you see, what is the appropriate protection against this type of attempted…

Blocking all DNS traffic would break legitimate name resolution across the network and does not address ICMP-based broadcast amplification attacks.

Disabling forwarding of unsolicited TCP requests targets TCP-based attacks such as SYN floods and is irrelevant to a Smurf attack, which uses ICMP over UDP/broadcast.

A Smurf attack works by sending ICMP Echo Requests to a subnet's broadcast address with the victim's IP spoofed as the source, causing every host on that subnet to reply to the victim and flood it. Disabling IP-directed broadcasts on the router (e.g., 'no ip directed-broadcast' in Cisco IOS) prevents the router from forwarding those broadcast packets to the subnet, stopping the amplification at the network layer. This is the standard, targeted countermeasure specifically designed for this class of attack.

Blocking UDP at the firewall is an overly broad measure that disrupts many legitimate services and does not specifically address ICMP broadcast amplification.