During the propagation of a nerve impulse, the action potential results from the movement of:

1. A
   ${\text{Na}}^{+}$ ions from extracellular fluid to intracellular fluid
2. B
   ${\text{K}}^{+}$ ions from extracellular fluid to intracellular fluid
3. C
   ${\text{Na}}^{+}$ ions from intracellular fluid to extracellular fluid
4. D
   ${\text{K}}^{+}$ ions from intracellular fluid to extracellular fluid