Which of the following is true for the ATP-sensitive potassium channel?

A. The channel is a spanning protein with a receptor site for ATP located on an extracellular region of the protein.

B. When blood plasma levels of glucose are very high, the potassium conductance of the ATP-sensitive potassium channels in the plasma membranes of beta-islet cells will be very high.

C. In smooth muscle cells surrounding an arteriole serving a region of the body that has just recently had very high levels of metabolism, the potassium conductance of the ATP-sensitive potassium channels in the plasma membranes of these smooth muscle cells will be very high.