Figure 12-2 The Nerve Action Potential

Use Figure 12-2 to answer the following questions:
-What is occurring in the area between #2 and #3?

A) An excitatory graded potential is occurring.
B) Potassium ions are entering the axon and causing depolarization.
C) Chemically gated sodium channels are open and sodium is diffusing into the axon.
D) Sodium ions are entering the axon and causing depolarization.
E) Repolarization of the axon due to sodium ions leaving the axon is occurring.