Answer: Option A
:
A
The pre synaptic neuron releases neurotransmitters into the synaptic cleft, these neurotransmitters then bind to the ligand gated channels, thus activating them. The ligand gated channels open up and allow the influx of sodium, which depolarizes the cell. This depolarization activates nearby voltage gated ion channels, which open up and let in even more sodium. Voltage gated sodium channels open up one region at a time, the previous region providing enough depolarization to activate the next regions voltage gated channels. This effectively allows the action potential to propagate through the cell.