An attacker uses a network sniffer to capture the packets of a transaction that adds $20 to a gift card. The attacker then user a function of the sniffer to push those packets back onto the network again, adding another $20 to the gift card. This can be done many times. Which of the following describes this type of attack? 

Answer options:

A. Integer overflow attack
B. Smurf attack
C. Replay attack
D. Buffer overflow attack
E. Cross-site scripting attack

C