Final answer:
The hypoglossal nerve (XII) is responsible for conducting motor impulses to the muscles of the tongue, enabling movements involved in speech and swallowing.
Step-by-step explanation:
The cranial nerve that conducts motor impulses to the tongue is the hypoglossal nerve (XII). The hypoglossal nerve is the twelfth cranial nerve and is responsible for the contraction of muscles of the tongue necessary for actions such as swallowing and speech. Other cranial nerves like the trigeminal (V), oculomotor (III), and vestibulocochlear (VIII) have different roles: the trigeminal nerve is related to facial sensation and masticatory muscles, the oculomotor nerve controls most of the eye muscles, and the vestibulocochlear nerve is involved in hearing and balance. The correct answer to the question, "Which cranial nerve conducts motor impulses to the tongue?" is a) Hypoglossal (XII).