Which cranial nerve is responsible for the sense of smell?

Cranial Nerve I, also known as the olfactory nerve, is indeed responsible for the sense of smell. It is the sensory nerve that carries olfactory information from the nasal mucosa, where smell receptors are located, directly to the brain. This nerve plays a crucial role in the perception of odors, making it essential for the sense of smell.

In contrast, Cranial Nerve II is the optic nerve, which is responsible for vision; Cranial Nerve III, the oculomotor nerve, controls eye movements and pupil constriction; and Cranial Nerve IV, the trochlear nerve, also relates to eye movement by supplying the superior oblique muscle. None of these cranial nerves are involved in the sense of smell, highlighting the unique function of Cranial Nerve I in olfaction.