Serum C3 is persistently low in the following except?

Ans. is 'a' i.e., Post streptococcal glomerulonephritisAlthough all conditions mentioned in the question are associated with low compliment levels 'persistently depressed levels' are not seen in post streptococcal glomerulonephritis.In post streptococcal glomerulonephritis : serum C3 levels are depressed within 2 weeks, however these usually return to normal levels within 6 to 8 weeksPersistently depressed levels after this period should suggest another cause such as presence of C3 nephritic factor (Membranoproliferative glomenulonephritis) - Harrison