cryptography question

[CISSP_Candidate]

What is the primary purpose of using one-way hashing on user passwords?

A. Minimizes the amount of primary and secondary storage needed to store passwords
B. Prevents anyone from reading passwords in plaintext
C. Avoids excessive processing required by an asymmetric algorithm
D. Prevents replay attacks

The answer is B but I could not understand we use hash for messeage integrity why its not D.

[Jescoi]

Yeah, I like B here. C and D could possibly be true, but if you read the question "What is the PRIMARY purpose of...," there is the one way BETTER answer of B.

So, focus on words like "primary" "best" "NOT" "except." Also, you will come across some questions that have two or maybe three answers that look pretty darn good at first glance. Take care when you read the exam questions, friends.

Good luck,