Sodium (Na⁺)is Unable to Cross a Membrane Until a Local

Multiple Choice

Sodium (Na⁺) is unable to cross a membrane until a local change in the membrane potential occurs.This suggests that Na⁺ transfer across membranes is controlled by a(n)

A) voltage-gated ion channel.
B) ligand-gated ion channel.
C) stretch-gated ion channel.
D) ion channel that is always open.
E) ion channel that is always closed.