Indicate the Mechanism Responsible for the Rapid Depolarization That Occurs

Multiple Choice

Indicate the mechanism responsible for the rapid depolarization that occurs as the "upsweep" of membrane potential peaks during the action potential.

A) closing of the voltage-gated Na⁺ channel activation gates
B) closing of the voltage-gated Na⁺ channel inactivation gates
C) opening of the voltage-gated K⁺ channel gates
D) both opening of the K⁺ channel gates and closing of the Na⁺ channel inactivation gates
E) both opening of the K⁺ channel gates and closing of the Na⁺ channel activation gates