This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Medicine
[{'content': 'Serum C3 is persistently low in the following except- \nSelect and explain. \nA. Post streptococcal glomerulonephritis, B. Membranoproliferative glomerulonephritis, C. ) Lupus nephritis, D. Glomerulonephritis related to bacterial endocarditis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Lupus nephritis: the significance of serological tests at the time of biopsy. ... As compared with a group of lupus patients without nephritis, patients with nephritis had lower serum complement C3 (p less than 0.05) and C4 (p less than 0.005) levels and higher serum DNA binding activity (p less than 0.001) Ref Harrison20th edition pg 277', 'role': 'assistant'}]