In the exhibit, the enterprise is running RSTP on all switches in its network and is currently experiencing Layer 2 loops.
The primary link is between switch 1 and switch 2. For redundancy, a secondary Layer 2 link is purchased from the provider.
The provider uses Q-in-Q tunneling to transport the enterprise’s Layer 2 frames.

Which action resolves the Layer 2 loop while maintaining backup connectivity?

A.
The provider enables Layer 2 protocol tunneling.

B.
You migrate the enterprise Layer 2 domain to MSTP.

C.
Enable the bpdu-time-out-action command on switch 3 and switch 4.

D.
Enable the bpdu-block command on switch 3 and switch 4.