In order for Sara, a client, to logon to her desktop computer, she must provide her username, password, and a four digit PIN. Which of the following authentication
methods is Sara using?

A.
Three factor

B.
Single factor

C.
Two factor

D.
Four factor

Explanation:
Single-factor authentication is when only one authentication factor is used. In this case, Something you know is being used as an authentication factor. Username,
password, and PIN form part of Something you know.
Incorrect Answers:
A: Three factor authentication is when three different authentication factors are provided for authentication purposes.
C: Two-factor authentication is when two different authentication factors are provided for authentication purposes.
D: Four factor authentication is when four different authentication factors are provided for authentication purposes.

Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, p 280.