21. For security attacks, which of the following is NOT true.
(A) Replaying attack includes several strategies to slow down or totally interruptthe service of the system.
(B) Snooping attack refers to unauthorized access to or interception of data. Anunauthorized entity may intercept the transmission and use the contents fortheir own benefit.
(C) Masquerading (spoofing) attack happens when the attacker impersonatessomebody else.
(D) Modification attack modifies the information to make it beneficial to theattackers.
(E) Repudiation attack is performed by one of the sender or the receiver to denythat the message has been sent or received.