What is a reason for an OSPF router to display a designated router ID of 0.0.0.0?

What is a reason for an OSPF router to display a designated router ID of 0.0.0.0?

A.
The MTU is mismatched.

B.
The subnet mask is mismatched.

C.
The interface type is point-to-point.

D.
The interface type is broadcast.

Explanation: