'Black water fever' is a serious complication of
Blackwater fever is a serious complication of malaria infection in which red blood cells burst in the bloodstream (hemolysis), releasing haemoglobin directly into the blood vessels and into the urine, frequently leading to kidney failure. Blackwater fever is caused by heavy parasitization of red blood cells with Plasmodium falciparum. So, the correct answer is 'Plasmodium falciparum'.