The plateau phase seen during the action potential of a cardiac muscle cell is due to the

A) sodium-potassium pump.
B) opening of Na⁺ channels.
C) continuing to have open Ca²⁺ channels.
D) closure of Cl⁻ channels.
E) closing of Ca²⁺ channels.

Plateau Phase

Prolongation of the depolarization phase of a cardiac muscle cell membrane; results in a prolonged refractory period.

Cardiac Muscle Cell

Cardiac muscle cell, also known as a cardiomyocyte, is a specialized type of muscle cell found in the heart that contracts to pump blood throughout the body.

Action Potential

The process by which nerve cells generate an electrical signal after being stimulated, involving a dramatic change in charge across the cell membrane.