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
[{'content': 'Which is the following is orally active direct Xa inhibitor? \nSelect and explain. \nA. Rivaroxaban, B. Agrataban, C. Dabigatran, D. Bilverudin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. a. RivaroxabanRivaroxaban, apixaban & edoxaban are factor Xa inhibitors.Dabigatran etexilate is direct thrombin inhibitor.', 'role': 'assistant'}]