The Following Question Refers to Comparative Concentrations, Permeabilities, and Potentials

The following question refers to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation by filling the appropriate letter in the blank using the following answer code:
-A. concentration of Na⁺ in the extracellular fluid
B. concentration of Na⁺ in the intracellular fluid of a nerve cell immediately following an action potential (assume that the Na⁺-K⁺ pump has not yet acted)

A) A is greater than B.
B) B is greater than A.
C) A and B are equal.