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: Pharmacology
Activity of extrinsic pathway of blood coagulation is measured by : 
Select and explain. 
A. Bleeding time, B. Prothrombin time/INR, C. aPTT, D. Thrombin time
B: Prothrombin time/INR
Answer: B: Prothrombin time/INR 
Explanation: None