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: Physiology
[{'content': 'Which of the following anticoagulant can be used as invivo and invitro also: \nSelect and explain. \nA. Heparin., B. Warfarin., C. Oxalates., D. EDTA.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Oxalates, citrates, EDTA are used as invitro anticoagulants.\nDicoumoral and warfarin are used as invivo coagulants.', 'role': 'assistant'}]