This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nephrotic and Nephritic syndrome, Subject name: Medicine
[{'content': 'Chronic reflux nephropathy causes: \nSelect and explain. \nA. Membranous nephropathy, B. Focal segmental GN, C. MPGN, D. Lipoid nephrosis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Causes of Secondary FSGS Drugs Viruses Hemodynamic factors - With reduced renal mass Hemodynamic causes - Without reduced renal mass Intravenous heroin Hepatitis B Solitary kidney Massive obesity Analgesics HIV Renal allograft Sickle cell nephropathy Pamidronate Parvovirus Renal dysplasia Lymphomas Lithium Renal Agenesis Anabolic steroids Segmental hypoplasia Vesicoureteric reflux', 'role': 'assistant'}]