what value to determine if a packet with the source IP of a gateway in the cluster is being spoofed?

Extended Cluster Anti-Spoofing checks what value to determine if a packet with the source
IP of a gateway in the cluster is being spoofed?

A.
The destination IP of the packet.

B.
The source MAC address of the packet.

C.
The source IP of the packet.

D.
The packet has a TTL value of less than 255.

Explanation: