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
Which of the following anticoagulant can be used as invivo and invitro also: 
Select and explain. 
A. Heparin., B. Warfarin., C. Oxalates., D. EDTA.
A: Heparin.
Answer: A: Heparin. 
Explanation: Oxalates, citrates, EDTA are used as invitro anticoagulants.
Dicoumoral and warfarin are used as invivo coagulants.