In order to walk, your brain sends a signal to your leg muscles. What allows this to happen?

A. Neurotransmitters diffuse across the membrane of neurons.

B. Neurotransmitters flow into the synapses through osmosis.

C. Neurons use active transport to move neurotransmitters against the concentration gradient and into the synapse.

D. Synapses diffuse across the membrane of neurons.

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.