Which of the following keyloggers can’t be detected by anti-virus or anti-spyware products?

Which of the following keyloggers can’t be detected by anti-virus or anti-spyware products?

A.
Hardware keylogger

B.
Software Keylogger

C.
Stealth Keylogger

D.
Convert Keylogger

Explanation:
A hardware keylogger will never interact with the operating system and therefore it will never be detected by any security programs running in the operating system.