<prompt> Which of the following drug is a direct inhibitor of clotting factor Xa?ApixabanArgatrobanFondaparinuxAspirin  <response>: Impoant ones are: - 1 Rivaroxaban 2 Apixaban 3 Edoxaban 4 Betrixaban a Argatroban - Direct thrombin inhibitor synthetic non-peptide compound which binds reversibly to the catalytic site of thrombin but not to the substrate recognition site b Fondaparinux - Indirect thrombin inhibitor. dAspirin - Inhibit COX and thus Thromboxane A2 synthesis inhibitor 