Which type of attack involves impersonating a user or a system? 

Answer options:

A. Smurfing attack
B. Spoofing attack
C. Spamming attack
D. Sniffing attack

B

A spoofing attack is when an attempt is made to gain access to a computer system by posing as an authorized user or system. Spamming refers to sending out or posting junk advertising and unsolicited mail. A smurf attack is a type of denial-of-service attack using PING and a spoofed address. Sniffing refers to observing packets passing on a network. Source: KRUTZ, Ronald L. & VINES, Russel
D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 77).