What is the best definition of the use of “Area 0” in OSPF?

What is the best definition of the use of “Area 0” in OSPF?

A.
Area 0 is used for administrative reasons, and is restricted from user definition.

B.
Area 0 is defined as the backbone, designed to be at the center of all routing updates and controls the dissemination of updates between areas.

C.
Area 0 is used to authenticate messages received from other routers in the same area.

D.
Area 0 is used for forwarding all routing updates received within the same Autonomous System from directly connected areas only.

E.
Area 0 allows for routing updates to be forwarded between different Autonomous Systems.