This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology, Subject name: Microbiology
[{'content': 'River blindness is caused by: \nSelect and explain. \nA. Onchocerca, B. Loa Loa, C. Ascaris, D. B. malayi', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Onchocerca(Ref: Harrison, 19th/e, p. 1421)* Onchocerciasis is also known as River blindness Q and fly involved is Simulium fly.", 'role': 'assistant'}]