Which structure picks up messages from outside the body and passes them to the brain?

• A. Sensory nerves
• B. Optic nerve
• C. Retina
• D. Middle ear

Answer: (A)

The question is about how sensory information from outside the body reaches the brain. Sensory nerves are the pathways that carry signals from receptors in the skin and other sense organs to the brain, letting you perceive touch, temperature, pain, and other external stimuli. The other options are more specialized parts: the optic nerve carries visual information from the retina to the brain, but isn’t a general external-sensing pathway; the retina detects light and sends signals but isn’t a nerve that passes messages on by itself; and the middle ear helps convert sound into neural signals for hearing, but the actual transmission to the brain occurs along the auditory nerves, not via the middle ear itself. Thus, the structure that picks up messages from outside and passes them to the brain is the sensory nerves.