When does a root-protected port transition back to the forwarding state?

When does a root-protected port transition back to the forwarding state?

A.
It does not transition back.

B.
It transitions after 20 seconds.

C.
It transitions when cleared by the operator.

D.
It transitions when superior BPDUs are no longer received.

Explanation:
Description – no-root-port

Configure an interface to be a spanning tree designated port. If the bridge receives more STP bridge protocol data units (BPDUs) on a root-protected interface, that interface transitions to a root-prevented STP state (inconsistency state) and the interface is blocked. This blocking prevents a bridge that should not be the root bridge from being elected the root bridge. When the bridge stops receiving more STP BPDUs on the root-protected interface, interface traffic is no longer blocked.