Final answer:
The anterior third of the tongue's taste sensations are provided by the facial nerve (cranial nerve VII), which is responsible for both sensory functions, such as taste, and motor functions, like facial expressions.
Step-by-step explanation:
The anterior two-thirds of the tongue's taste sensations are provided by the facial nerve (cranial nerve VII), not the fifth (trigeminal), ninth (glossopharyngeal), eighth (vestibulocochlear), or twelfth (hypoglossal) cranial nerves. Therefore, the correct answer to the student's question is (A) Fifth which is actually a mistake and should be the Facial nerve or Cranial Nerve VII.
The facial nerve's role is both sensory, providing taste sensations, and motor, controlling muscles for facial expressions. The glossopharyngeal nerve (cranial nerve IX) also plays a role in taste, but it is responsible for the sensations of the posterior one-third of the tongue. In contrast, the hypoglossal nerve (cranial nerve XII) is purely a motor nerve that controls the movements of the tongue muscles.