What Would Happen If the G-Protein Coupled Receptor in Heart

Multiple Choice

What would happen if the G-protein coupled receptor in heart cells that binds to ACh had a mutation that caused it to bind more tightly to the G-protein alpha subunit?

A) G-protein activation and K+ channel opening would happen more quickly.Heart rate may remain abnormally low,impairing response to stress.
B) This would lead to K+ flow out of heart cells,causing increased hyperpolarization.
C) G-protein activation and K+ channel opening would be slowed.Heart rate may remain abnormally high,especially following stress.
D) This would lead to K+ flow into heart cells,causing increased depolarization.