This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins, Subject name: Biochemistry
Which water soluble vitamin is synthesized in our body - 
Select and explain. 
A. Niacin, B. Folic acid, C. Cobalamine, D. Pyridoxine
A: Niacin
Answer: A: Niacin 
Explanation: Ans. is 'a' i.e., Niacin o This question is confusing one (Read text below)o Niacin (Vitamin B3) is synthesized from tryptophan inside the bodo Some vitamins are also formed by bacterial activity in coloni) Vitamin Kii) Vitamin B12Thiamin (Vitamin Bl)iv) Riboflavin (Vitamin B2)v) Biotin (Vitamin B7)o Thus, options a, b & d all are correct here. But best answer among these is niacin as it is the only vitamin which is synthesized by proper anabolic metabolism.