This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'Black water fever is caused by: \nSelect and explain. \nA. Plasmodium vivax, B. Plasmodium falciparum, C. Leishmania donovani, D. Microfilaria', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]