Which of the following is an ip address that is private (i.e. reserved for internal networks, and not a
valid address to use on the internet)?

A.
172.12.42.5

B.
172.140.42.5

C.
172.31.42.5

D.
172.15.45.5

Explanation:
The Internet Assigned Numbers Authority (IANA) has reserved the following three
blocks of the IP address space for private Internets – 10.0.0.0 to 10.255.255.255, 172.16.0.0 to
172.31.255.255, and 192.168.0.0 to 192.168.255.255- that are known as “global non-routable
addresses.”” Pg. 94 Krutz: The CISSP Prep Guide.