Task: Question Answering
Input (English): Question: Which of the following pairings between anticoagulant drug and mechanism of action is INCORRECT? 
 Options:  <1> Heparin - cofactor of antithrombin III. <2> Acenocoumarol - inhibits vitamin K epoxide reductase. <3> Dabigatran - inhibits thrombin. <4> Rivaroxaban - inhibits factor Xa. <5> Warfarin - inhibits the absorption of vitamin K.
Output (English): 5