John Notices That the Hard Disk on His New Computer

Multiple Choice

John notices that the hard disk on his new computer is very active even though he isn't doing anything on the computer and it isn't connected to the Internet. What is the most likely suspect?

A) A disk failure is imminent.
B) TCP/IP hijacking is being attempted.
C) Thesystem is under a DoS attack.
D) A virus is spreading on his system.