Which of the following nerves is solely responsible for taste?

The facial nerve, also known as cranial nerve VII, plays a crucial role in the sense of taste. It innervates the taste buds located on the anterior two-thirds of the tongue, providing the ability to perceive sweet, salty, and sour flavors. This nerve facilitates sensory functions related to taste through its chorda tympani branch, which specifically transmits taste sensations from these regions to the brain.

While other nerves, such as the glossopharyngeal and vagus nerves, are involved in taste perception as well, they are not solely responsible for this function. The glossopharyngeal nerve primarily covers the posterior one-third of the tongue, and the vagus nerve also has taste fibers but serves a broader range of functions, including autonomic control to various organs. The accessory nerve, however, is not involved in taste at all, as it primarily provides motor innervation to certain muscles in the neck and shoulders.

Therefore, the facial nerve is the correct answer because it is the main cranial nerve responsible for taste sensation in a specific and significant region of the tongue, making it highly specialized for this sensory function.