Van has had difficulty sleeping since he took a hard hit to his head in a football game this fall. van has most likely sustained damage to

The answer is reticular formation. It comprises most of the brain stem and one of the critical region for functioning.It is a collection of neurons regulating different autonomic functions namely sleeping and waking thus in the scenario since Van had difficulty sleeping when he was hit at his head surely he did sustain a damage.

The answer is option a