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
Which is the following is orally active direct Xa inhibitor? 
Select and explain. 
A. Rivaroxaban, B. Agrataban, C. Dabigatran, D. Bilverudin
A: Rivaroxaban
Answer: A: Rivaroxaban 
Explanation: Ans. a. RivaroxabanRivaroxaban, apixaban & edoxaban are factor Xa inhibitors.Dabigatran etexilate is direct thrombin inhibitor.