This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition, Subject name: Medicine
[{'content': 'Magenta red tongue with cheilosis is caused by deficiency of? \nSelect and explain. \nA. Thiamine, B. Riboflavin, C. Cyanocobalamine, D. Ascorbic acid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. RiboflavinNutrientClinical findingDietary level per day associated with overt deficiency in adultsContributing factors to DeficiencyRiboflavinMagenta tongue, angular stomatitis, seborrhoea, cheilosis<0.6mg-', 'role': 'assistant'}]