The correct answer is: D) thalamus.
Thalamus is a brain structure located in the rostral end of the brainstem. Thalamus is an important relay and integrative station. It connects parts of the nervous system. Sensory signals and motor information go to the thalamus and then pass to all areas of the cerebral cortex, hypothalamus, brainstem, basal ganglia.
Thalamus is a mass of gray matter that regulates consciousness, sleep, and alertness.