To put extra password security to your networks you would make use of encryption.

What does it means?

A.
The password is mangled it in such a way as to make it meaningless

B.
You should make the password longer

C.
It is passwords, that is provided by S/key

D.
None of the above.

Explanation:
Encryption is the process of taking a standard password, and garbling it in such a way as to make it meaningless to sniffers, crackers, or other eavesdroppers.
Incorrect
Answers:
B: This is to make the password difficult to crack. It has nothing to do with encryption.
C: One-time passwords, is provided by the S/key
References:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 467