CompTIA A+ 220-902

Answer: A - Root kits are software programs that have the ability to hide certain processes and connections from the operating system.

Key Takeaway:
A root kit is a software system consisting of one or more programs designed to obscure the fact that a system has been compromised. An attacker may use a root kit to replace vital system executables, which may then be used to hide processes and files the attacker has installed, along with the presence of the root kit. These hidden things do not show up in Task Manager or the netstat display. It manipulates function calls to the operating system and filters out information that would not appear when a computer is functioning normally.