The _____ is a small brain structure that uses input from the retina to synchronize its own rhythm with the daily cycle of light and dark.

A) cerebellum
B) suprachiasmatic nucleus
C) prefrontal cortex
D) corpus callosum

Suprachiasmatic Nucleus

A tiny region of the brain in the hypothalamus, responsible for controlling circadian rhythms, essentially functioning as the body's internal clock.

Retina

The multilayered light-sensitive surface in the eye that records electromagnetic energy and converts it to neural impulses for processing in the brain.