Refer to the exhibit.&

Refer to the exhibit. In the diagram， the switches are running IEEE 802.1s MST. Which ports are in the MST blocking state？（）

• A GE-1/2 and GE 2/1
• B GE-1/1 and GE-2/2
• C GE-3/2 and GE 4/1
• D no ports are in the blocking state
• E There is not enough information to determine which ports are in the blocking state.