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: Gynaecology & Obstetrics
A 28 years old female presented with the history of recurrent aboions, pain in calves for 4 years. Patient is suffering from congenital deficiency of: 
Select and explain. 
A. Protein C, B. Thrombin, C. Plasmin, D. Factor XIII
A: Protein C
Answer: A: Protein C 
Explanation: Answer- A (Protein C)'Inherited thrombophilia causes both early and late miscarriages due to intravascular thrombosis. Protein C resistance (factor V Leiden mutation) is the most common causeProtein C is the natural inhibitor or coagulation - Dutta