Which nerve carries impulses from the retina to the brain?

• A. Olfactory nerve
• B. Optic nerve
• C. Facial nerve
• D. Trigeminal nerve

Answer: (B)

The optic nerve is the correct answer because it is specifically responsible for transmitting visual information from the retina, where light is converted into neural signals, directly to the brain. Once the photoreceptors in the retina detect light, they send these signals through the optic nerve to the visual cortex, allowing for the perception of images.

In contrast, the olfactory nerve is involved in the sense of smell and transmits signals from the nasal cavity to the brain. The facial nerve primarily controls the muscles of facial expression and is related to taste sensation from the anterior two-thirds of the tongue. The trigeminal nerve is responsible for sensation in the face and motor functions such as biting and chewing. Each of these nerves has distinct roles in sensory and motor functions unrelated to vision, making the optic nerve the sole pathway for visual information processing.