Which statement correctly identifies Class B addresses and their default mask?

• A. Class B addresses range 0.0.0.0 to 127.255.255.255; default 255.0.0.0
• B. Class B addresses range 128.0.0.0 to 191.255.255.255; default 255.0.0.0
• C. Class B addresses range 128.0.0.0 to 191.255.255.255 with default 255.255.0.0
• D. Class B addresses range 128.0.0.0 to 191.255.255.255; default 255.255.255.0

Answer: (C)

The main idea here is understanding IPv4 classful addressing and the default subnet masks that go with each class. Class B uses addresses where the first octet is between 128 and 191 inclusive. The default subnet mask for Class B is 255.255.0.0, meaning the network portion is the first two octets and the last two octets identify hosts within that network. Therefore, the range 128.0.0.0 to 191.255.255.255, with the default mask 255.255.0.0, correctly identifies Class B addresses and their standard mask.

The other possibilities mix ranges or masks from different classes (for example, Class A’s range with a Class B mask, or a Class C-style mask), which is why they don’t fit. The correct combination aligns the 128–191 range with the 255.255.0.0 mask.