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
Magenta tongue and cracks at corner of mouth are seen in deficiency of: 
Select and explain. 
A. Vitamin B1, B. Niacin, C. Riboflavin, D. Pantothenic acid
C: Riboflavin
Answer: C: Riboflavin 
Explanation: None