What is the feature of a digital signature that ensures the sender cannot later deny generating and sending the message called?

C. nonrepudiation.

All of the above are features of a digital signature. Nonrepudiation ensures that the claimed sender cannot later deny generating and sending the message. Data integrity refers to changes in the plaintext message that would result in the recipient failing to compute the same message hash. Since only the claimed sender has the key, authentication ensures that the message has been sent by the claimed sender. Replay protection is a method that a recipient can use to check that the message was not intercepted and replayed.