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
Patient with deficiency of Vitamin K, pre surgical
test required is 
Select and explain. 
A. PT time, B. Bleeding time, C. Clotting time, D. bleeding index
A: PT time
Answer: A: PT time 
Explanation: None