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 is found in the deficiency of the vitamin 
Select and explain. 
A. Riboflavin, B. thiamine, C. nicotinic acid, D. pyridoxine
A: Riboflavin
Answer: A: Riboflavin 
Explanation: None