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
Warfarin mechanism of action ? 
Select and explain. 
A. Chelating Ca, B. Inhibiting antithrombin III, C. Inhibiting Vitamin K dependent carboxylation, D. Inhibiting thrombin
C: Inhibiting Vitamin K dependent carboxylation
Answer: C: Inhibiting Vitamin K dependent carboxylation 
Explanation: Ans. is 'c' i.e., Inhibiting Vitamin K dependent carboxylation Warfarin inhibits vitamin K dependent carboxylation of clotting factors by inhibiting the enzyme Vitamin K epoxide reductase.