Question

john was startled when the door slammed shut. what part of the brainstem is responsible for the auditory reflex? midbrain thalamus medulla pons

Explanation:

The midbrain contains the inferior colliculi, which are responsible for auditory reflexes. The thalamus is a sensory relay station but not part of the brainstem. The medulla controls vital functions like breathing and heart rate. The pons is involved in sleep and arousal and some motor/sensory functions but not specifically auditory reflexes.

Answer:

Midbrain