You want to put a web server online for public use. Which IP address would you use?

A. 192.168.34.34
B. 172.31.54.3
C. 10.55.33.32
D. 198.168.55.45

D. 198.168.55.45 is a valid IPv4 public address. All of the other addresses are RFC 1918 compliant and thus non-routable on the Internet.

Class A 10.0.0.0 – 10.255.255.255
Class B 172.16.0.0 – 172.31.255.255
Class C 192.168.0.0 – 192.168.255.255