Which statement describes the rule of split horizon?

A.
Only routers can split boundaries (horizons) between concentric networks.

B.
All distance vector protocols require fall back routes that may cause momentary loops as the
topology changes.

C.
Networks can only remain fully converged if all information about routes is sent out all active
interfaces.

D.
Information about a route should not be sent back in the direction from which the original
update came.

E.
Each AS must keep routing tables converged to prevent dead routes from being advertised
across the AS boundary.