A. Neurotransmitters diffuse across the membrane of neurons
Explanation:
When we begin to move, the brain initially sends a signal to the spinal cord, then the nerve cells in the spinal cord monitor the exact coordination of the muscles. Signal from the brain and the spinal cord directs the movement of leg muscles. Signal is transmitted by release of neurotransmitter from the neuron to the synaptic cleft and its binding to the receptor of adjacent neuron.