<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 25-year-old man is admitted to the hospital after a severe motor vehicle accident as an unrestrained front-seat passenger. Appropriate life-saving measures are given, and the patient is now hemodynamically stable. Physical examination shows a complete loss of consciousness. There are no motor or ocular movements with painful stimuli. The patient has bilaterally intact pupillary light reflexes. The patient is placed in a 30 semi-recumbent position for further examination. What is the most likely finding on the examination of this patients right ear?? A: Cold water causing ipsilateral saccadic movement., B: Warm water causing ipsilateral slow pursuit., C: Warm water causing ipsilateral saccadic movement., D: Warm water mimicking the head turning left., E: Cold water causing contralateral slow pursuit.,  <response>: This is a clinical vignette describing a 25-year-old man who was in a severe motor vehicle accident and is now hemodynamically stable but has a complete loss of consciousness with no motor or ocular movements to painful stimuli. He has intact pupillary light reflexes bilaterally. The question asks about the most likely finding when examining his right ear. The intact pupillary light reflexes indicate the midbrain is functioning. The lack of motor or ocular movements to painful stimuli indicates damage to the corticospinal and cortical pathways. This clinical picture is most consistent with a diagnosis of coma due to traumatic brain injury. When examining the ear in a comatose patient, caloric testing can help determine brainstem function. In caloric testing, irrigation of the ear canal with warm or cold water causes movement of the endolymph in the semicircular canals, which activates the vestibular nuclei in the brainstem. This normally elicits slow, pursuit-like eye movements to the side opposite the ear being stimulated. Lack of response indicates damage to the brainstem.C: Warm water causing ipsilateral saccadic movement. 