Which options are true regarding OSPF neighborship requirements?

A) Routers must be in the same ASN.
B) Routers must have matching K-values.
C) Routers must be in the same Process-ID.
D) Routers must have matching timers.
E) Routers must be in a common IPv4 subnet.
F) Routers must be in the same area.

D, E, F
Explanation: D) OSPF neighborship has a number of requirements including that the routers must be connected by an operational interface, not have its traffic blocked by an ACL, must be in a common IPv4 subnet, must be in the same OSPF area, must have a unique router-ID, and must have matching timers.
E) OSPF neighborship has a number of requirements including that the routers must be connected by an operational interface, not have its traffic blocked by an ACL, must be in a common IPv4 subnet, must be in the same OSPF area, must have a unique router-ID, and must have matching timers.
F) OSPF neighborship has a number of requirements including that the routers must be connected by an operational interface, not have its traffic blocked by an ACL, must be in a common IPv4 subnet, must be in the same OSPF area, must have a unique router-ID, and must have matching timers.