<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 47-year-old homeless man is brought to the emergency department by police, who found him sleeping by the side of the street. He is somnolent and confused and is unable to give a reliable history. His medical history is unobtainable. Vital signs include: temperature 36.9C 98.4F, blood pressure 11275 mm Hg, and pulse 85min. Physical examination reveals that he has severe truncal ataxia and horizontal gaze palsy with impaired vestibulo-ocular reflexes. Muscle stretch reflexes and motor strength are normal. He has no sensory deficits. Which of the following best represents the most likely etiology of this patients condition?? A: Delirium tremens, B: Miller-Fisher syndrome, C: Vitamin B1 deficiency, D: Vitamin B12 deficiency, E: Ethylene glycol intoxication,  <response>: Based on the information provided in the question stem, the key findings are:- Homeless man with somnolence, confusion, truncal ataxia, and horizontal gaze palsy - Impaired vestibulo-ocular reflexes- Normal muscle strength and reflexes, no sensory deficits- Unable to obtain medical history or etiologyThe horizontal gaze palsy and impaired vestibulo-ocular reflexes indicate a problem with the brainstem and cerebellum. Ataxia also indicates cerebellar dysfunction. The normal strength and reflexes localize this to the cerebellum and brainstem rather than a peripheral neuropathy or spinal cord lesion. Of the choices given, vitamin B1 thiamine deficiency best matches the clinical presentation described. Thiamine deficiency can lead to Wernicke encephalopathy which classically causes ataxia, ophthalmoplegia, and confusion. The other choices do not match the localization in the brainstem and cerebellum.C: Vitamin B1 deficiency 