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