The routable public class A address is

Class A addresses range from 0.0.0.0 through 126.255.255.255 and use a default subnet mask
of255.0.0.0. The routable public class A address is

A.
19.16.18.255

B.
10.0.0.255

C.
19.16.18.1

D.
10.0.0.10