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
The triad of &;diarrhea, dementia, and dermatitis&; is characteristically seen in the deficiency of vitamin _______________ 
Select and explain. 
A. Riboflavin, B. Niacin, C. Thiamine, D. Pyridoxine
B: Niacin
Answer: B: Niacin 
Explanation: Niacin deficiency results in pellagra.The early symptoms are vague. Anorexia, lassitude, weakness, burning sensations numbness and dizziness may be prodromal symptoms, After a long period of deficiency, the classic triad of dermatitis, diarrhea and dementia appears. Ref: Page 182; Nelson textbook of pediatrics; 17th edition