A reflex arc consists of

a. afferent neuron

b. efferent neuron

c. interneuron

d. all of the above

e. a and b only

All of the above.

Explanation:

Reflex arc may be defined as the neural pathway that control the function of the reflex system of the body. Two main types of reflex arc are somatic reflex arc and autonomic reflex arc.

The afferent neuron carries signal from the receptors to the integrating center via the interneuron. The efferent neuron carries signal from the integrating center to the effector organ via the inter neuron.

Thus, the correct answer is option (e).