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: Pathology
Bald tongue of sandwith is seen in deficiency of 
Select and explain. 
A. Niacin, B. Riboflavin, C. Vitamin B12, D. None of the above
A: Niacin
Answer: A: Niacin 
Explanation: None