Which Answer Explains Why Na+ Ions Enter the Cell When

Multiple Choice

Which answer explains why Na+ ions enter the cell when voltage-gated Na+ channels are opened in neurons?

A) the Na+ concentration is much lower outside the cell than it is inside the cell
B) the Na+ ions are actively transported by the sodium-potassium pump into the cell
C) the Na+ concentration is much higher outside the cell than it is inside, and the Na+ ions are attracted to the negatively charged interior
D) the Na+ concentration is much higher outside the cell than it is inside, and the Na+ ions are actively transported by the sodium-potassium pump into the cell