The Stoichiometry of the NCX Is

The stoichiometry of the NCX is

A) 3 Na⁺ ions for every Ca²⁺ ion
B) 2 Na⁺ ions for every Ca²⁺ ion
C) 1 Na⁺ ion for every Ca²⁺ ion
D) 3 Na⁺ ions for every 2 Ca²⁺ ions
E) 2 Na⁺ ions for every 2 Ca²⁺ ions