Refer to the exhibit. Which statement about switch S1 is true?
A. Physical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 2 port-channel interface using an open standard protocol.
B. Logical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 2 physical port- channel interface using a Cisco proprietary protocol.
C. Physical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 3 port-channel interface using a Cisco proprietary protocol.
D. Logical port Fa0/13, Fa0/14, and Fa0/15 successfully formed a Layer 3 physical port- channel interface using an open standard protocol.
