Indicate Whether the Membrane Is More Permeable to K⁺ or to Na⁺

Indicate whether the membrane is more permeable to K⁺ or to Na⁺ or is equally permeable to these ions under the stated conditions by writing the appropriate letter in the blank using the following answer code:
-during the falling phase of an action potential

A) The membrane is more permeable to K⁺ than to Na⁺.
B) The membrane is more permeable to Na⁺ than to K⁺.
C) The membrane is about equally permeable to Na⁺ and K⁺.