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
Histidine load test is done for 
Select and explain. 
A. Histidine deficiency, B. Folic acid deficiency, C. Glutamate deficiency, D. Vitamin B12 deficiency
B: Folic acid deficiency
Answer: B: Folic acid deficiency 
Explanation: Histidine load test / FIGLU test.