This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
[{'content': 'All of the following are true about alcohol abuse except \nSelect and explain. \nA. Alcoholic hallucinosis is seen after 12-24 hours of alcohol withdrawl, B. MCV is decreased in chronic alcoholics, C. Widmark formula is used to calculate blood alcohol concentration, D. CAGE questionnaire is used as screening test for alcohol abuse', 'role': 'user'}, {'content': 'Answer: B \nExplanation: MCV\xa0is found to be elevated because of dietary deficieny & impaired absorption of Folic acid in chronic alcoholics.', 'role': 'assistant'}]