Interruption attacks are also called attacks:
a) masquerade
b_ alteration
c) denial of service
d) replay attacks

Interruption attack are also referred to as Denial Of Service(DOS) attack.

Explanation:

Interruption attack are also called denial of service.The main aim of  interruption attack or Denial Of Srvice attack is to make resources unavailable.

For example:- wordpress.com had an DOS attack that took down their servers hence the service was unavailable for it's users.

Hence we conclude that the answer to this question is Denail of Service (DOS).