Assuming only one VLAN in the exhibit, which switch is acting as the root bridge?

A.
Switch3

B.
A root bridge is not required in this network.

C.
Switch1

D.
Switch2

Explanation:
A root switch has all ports in non-blocking mode. Based on the diagram above, Switch1 and
Switch 2 contain ports that have been blocked by the STP process, so Switch3 must be the root
bridge.