Which nerves should be stimulated to exercise the superficial muscles of facial expression?

The facial nerve is the correct choice because it is specifically responsible for the movement of the muscles of facial expression. This cranial nerve, also known as cranial nerve VII, innervates various muscles that allow us to express emotions such as smiling, frowning, and raising eyebrows. Stimulating the facial nerve can effectively engage and exercise these superficial muscles.

Motor nerves control muscle movements, but they encompass a broader range than just the facial muscles. Sensory nerves are primarily involved in transmitting sensory information from the body to the brain rather than controlling muscle movement. Spinal nerves connect the spinal cord to the rest of the body and are not directly responsible for facial expressions. Therefore, focusing on the facial nerve ensures precise stimulation of the muscles responsible for facial expressions.