<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A middle aged man is brought in by emergency medical services after being found unconscious, lying on the street next to an empty bottle of vodka. His past medical history is unknown. Upon evaluation, he opens his eyes spontaneously and is able to obey commands. After peripheral access is obtained, IV normal saline and glucose are administered. Suddenly, the patient becomes confused and agitated. Horizontal nystagmus is noted on exam. This acute presentation was likely caused by a deficiency in which of the following?? A: Vitamin A, B: Vitamin B12, C: Vitamin B9, D: Vitamin B6, E: Vitamin B1,  <response>: This is a question about identifying the likely vitamin deficiency in a middle aged man found unconscious after drinking alcohol. The key details are that he was drinking alcohol, became confused and agitated after initial improvement, and had horizontal nystagmus. These symptoms point to a deficiency in vitamin B1, also known as thiamine. Thiamine deficiency is common in alcoholics and can lead to Wernicke-Korsakoff syndrome, which presents with confusion, ataxia, and eye movement abnormalities like nystagmus. Choices A, B, C, and D can be ruled out as they do not match this presentation.E: Vitamin B1 