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: Biochemistry
FIGLU excretion test is to estimate deficiency of 
Select and explain. 
A. Vitamin K, B. Vitamin B12, C. Vitamin folic acid, D. Niacin
C: Vitamin folic acid
Answer: C: Vitamin folic acid 
Explanation: None