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: Surgery
[{'content': "Deep venous thrombosis is caused by all EXCEPT: March 2013 (a, e) \nSelect and explain. \nA. Lower limb trauma, B. Cushing's syndrome, C. Subungual hematoma, D. Hip & pelvic surgeries", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C i.e. Subungual hematoma Deep venous thrombosis Clinical presentation: - Unilateral leg swelling, Local warmth, - Erythema & - Pain Non-invasive test to diagnose DVT: Duplex venous USG Drug used for DVT prophylaxis: Heparin Treatment: - Thrombolytic therapy, - Bandaging etc. Homans sign in DVT: Forced dorsiflexion of foot causes calf pain', 'role': 'assistant'}]