What type of response does the glossopharyngeal nerve primarily control?

The glossopharyngeal nerve plays a crucial role in the sensation of taste, particularly from the posterior part of the tongue. It is responsible for relaying taste information from specifically the taste buds located in that region. This nerve also contributes to other functions such as providing sensory input from the throat and aiding in swallowing; however, its primary role among the options given is related to taste sensation.

The other options relate to functions controlled by other cranial nerves. Vision processing falls under the responsibility of the optic nerve, facial movement is governed by the facial nerve, and hearing impulses are primarily transmitted by the vestibulocochlear nerve. Thus, the glossopharyngeal nerve's association with taste sensation from the middle to back of the tongue is what makes it the correct choice in this context.