What is the default subnet mask for a Class B network?

What is the default subnet mask for a Class B network?

A.
255.0.0.0

B.
255.255.0.0

C.
255.255.255.0

D.
255.255.255.255

Explanation:
Categorizing IPv4 Addresses

The IPv4 classification system is known as the classful network architecture and is broken down into five sections. Class B has a default subnet mask
of 255.255.0.0.