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': 'Most common cause of AVN of the hip is \nSelect and explain. \nA. Idiopathic, B. Alcoholism, C. Caissons Disease, D. Fracture neck of femur', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer- A. IdiopathicCauses ofAVN hipldiopathic (most common)Infection- septic ahritis, osteomyelitisHematological malignancies- leukemia, lymphomaAlcohol,coicosteroidsSLEPregnancyCassions diseaseHyperlipidemiaPehes diseasIonising radiation', 'role': 'assistant'}]