You work as network consultant. Your customer, TestKing Inc, has a class C network license. TestKing wants you to subnet the network to provide a separate subnet for each of its 5 departments. Each subnet must support at least 24 hosts.
Which network mask should you use?（）

A.255.255.255.192
B.255.255.255.224
C.255.255.255.240
D.255.255.255.248
E.255.255.255.252
F.255.255.255.254