Which of the following statements regarding the router ID in OSPF are incorrect? (Choose three)

A.
The router IDs of OSPF routers in the same area must be the same, but can be different in different areas.

B.
The router ID must be the IP address of an OSPF router interface.

C.
The router ID must be configured manually.

D.
A router running OSPF must have a router ID for it to operate properly.

Explanation: