This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vascular surgery, Subject name: Surgery
Which one of the following does not cause deep vein thrombosis 
Select and explain. 
A. Estrogen, B. Thrombocytosis, C. Venous stasis, D. Sickle cell Anemia
D: Sickle cell Anemia
Answer: D: Sickle cell Anemia 
Explanation: Sickle cell anemia does not cause DVT. They cause vaso-occlusive crisis by plugging the microcirculation (aggregate of Sickle cell are formed in the capillaries because of hypoxia).