An action potential in the nerve fibre is produced when positive and negative charges on the outside and the inside of the axon membrane are reversed, because

Options

A. More potassium ions enter the axon as compared to sodium ions leaving it
B. More sodium ions enter the axon as compared to potassium ions leaving it
C. All potassium ions leave the axon
D. All sodium ions enter the axon

Answer

B

Explanation

During the depolarization, more and more sodium channels open which increase sodium conductance (i.e. influx of `Na^(+)`) about 20 times of that during rest potential.