​The descending phase of the nerve action potential is caused by:​

​A. delayed opening of voltage-gated $$K^+$$ ion channels.

B. rapid opening of voltage-gated $$Na^+$$ ​ion channels.​

​C. closing of voltage-gated ​$$Na^+$$ ion channels.​

​D. leaky ​$$K^+$$ ion channels.​

​Which one of the following options represents the combination of correct statements?​

Correct option is B

EXPLANATION-

Statement  A - Delayed opening of voltage-gated K⁺ ion channels , allowing potassium to leave the cell, making the inside more negative again. This statement is Correct.

​Statement B - Rapid opening of voltage-gated Na⁺ ion channels . This happens during the rising phase, not the descending phase. So this statement is incorrect

Statement C - Closing of voltage-gated Na⁺ ion channels. so sodium stops entering the cell. This statement is correct.

Statement D- Leaky K⁺ ion channels . These contribute to resting membrane potential, not the descending phase of the action potential. So this statement is incorrect

So, the correct option is (b) A and C only