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: Orthopaedics
A patient of nephrotic syndrome taking steroids for 6 years presented with a limping gait and of limitation of abduction and internal rotation. He most probably has - 
Select and explain. 
A. Primary osteoarthritis, B. Avascular necrosis, C. Tuberculosis, D. Aluminum toxicity
B: Avascular necrosis
Answer: B: Avascular necrosis 
Explanation: None