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
Chronic reflux nephropathy causes: 
Select and explain. 
A. Membranous nephropathy, B. Focal segmental GN, C. MPGN, D. Lipoid nephrosis
B: Focal segmental GN
Answer: B: Focal segmental GN 
Explanation: 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