Which of the following IPv4 addresses has a subnet mask 255.0.0.0? (Choose all that apply)

(A) 188.187.186.185
(B) 204.203.202.201
(C) 55.44.22.11
(D) 10.0.0.56
(E) 100.24.5.56
(F) 192.168.178.6

C, D, and E are the correct answers.

Description	Class A	Class B	Class C
First octet range	1 – 126	128 – 191	192 – 223
Valid network numbers	1.0.0.0 – 126.0.0.0	128.0.0.0 – 191.255.0.0	192.0.0.0 – 223.255.255.0
Default mask	255.0.0.0	255.255.0.0	255.255.255.0