This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
What amount of Tryptophan produces 1gm of niacin? 
Select and explain. 
A. 40mg, B. 50mg, C. 60mg, D. 70mg
C: 60mg
Answer: C: 60mg 
Explanation: Niacin (1 mg of niacin is formed from 60 mg of tryptophan).