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
Drug of choice for deep vein thrombosis prophylaxis in surgical patients is : 
Select and explain. 
A. Intravenous unfractionated heparin, B. Subcutaneous unfractionated heparin, C. Subcutaneous low molecular weight heparin, D. Warfarin
D: Warfarin
Answer: D: Warfarin 
Explanation: None