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
Niacin deficiency causes all except 
Select and explain. 
A. Dermatitis, B. Dactylitis, C. Diarrhea, D. Dementia
B: Dactylitis
Answer: B: Dactylitis 
Explanation: The classic triad of pellagra is dermatitis, diarrhea, and dementia. Ref: Page 182; Nelson textbook of pediatrics; 17th edition