The Motor Unit Is the Elementary Functional Unit of the Peripheral

The motor unit is the elementary functional unit of the peripheral nervous system.What are its four elements?

A) The cell body of the motor neuron in the anterior horn of the spinal cord; the axon of the motor neuron, which travels via spinal nerves and peripheral nerves to muscle; the neuromuscular junction; and the muscle fibers innervated by the neuron
B) The spinal nerve, the peripheral nerve, the neuromuscular junction, and the muscle fibers
C) The cell body of the motor neuron in the posterior spinal cord, the dorsal root, the peripheral nerve, and the muscle fibers
D) The synaptic junction, the anterior spinal cord, the neuromuscular junction, and the muscle fibers