This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
The clot formed after coagulation cascade is not stable unless extensive cross linking occurs .this is done by 
Select and explain. 
A. Plasmin, B. Thrombin, C. Factor 8, D. High molecular weight kininogen
B: Thrombin
Answer: B: Thrombin 
Explanation: Ref Robbins 9/e p119 Thrombin is the principal enzyme of hemostasis. It catalyzes the conversion of fibrinogen to fibrin and activates procoagulant factors V, VIII, XI, and XIII. Additionally, when bound to thrombomodulin, it activates protein C, an anticoagulant zymogen