Which of the following security threats does NOT use software to extract sensitive information or credentials?

Which of the following security threats does NOT use software to extract sensitive
information or credentials?

A.
Grayware

B.
Shoulder surfing

C.
Malware

D.
Man-in-the-Middle exploits

Explanation:

Reference:
http://searchsecurity.techtarget.com/definition/shoulder-surfing