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: Pediatrics
[{'content': 'Niacin deficiency causes all except \nSelect and explain. \nA. Dermatitis, B. Dactylitis, C. Diarrhea, D. Dementia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The classic triad of pellagra is dermatitis, diarrhea, and dementia. Ref: Page 182; Nelson textbook of pediatrics; 17th edition', 'role': 'assistant'}]