Certified Ethical Hacker 312-50v10 – Question045

Bob, your senior colleague, has sent you a mail regarding aa deal with one of the clients. You are requested to accept the offer and you oblige.
After 2 days, Bob denies that he had ever sent a mail.
What do you want to know to prove yourself that it was Bob who had send a mail?

B. Integrity
C. Non-Repudiation
D. Authentication

Correct Answer: C