Which statement is true?

Refer to the exhibit.

Which statement is true?
A . The Fa0/11 role confirms that Switch A is the root bridge for VLAN 20.
B . VLAN 20 is running the Per VLAN Spanning Tree Protocol
C . The MAC address of the root bridge is 0017.596d.1580.
D . Switch A is not the root bridge, because not all of the interface roles are designated

Answer: D