Which Statement Best Describes Spyware

Multiple Choice

Which statement best describes spyware?

A) It is software that secretly gathers information about users while they browse the Web.
B) It is an attack that floods a server with service requests to prevent legitimate users' access to the system.
C) It is encryption security that manages transmission security on the Internet.
D) It is a programming routine built into a system by its designer to bypass system security and sneak back into the system later to access programs or files.