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': 'Kallu, a 30-year-old man, presented with subcutaneous itchy nodules over the left iliac crest. On examination they are firm, non tender and mobile. Skin scraping contains microfilaria and adult worms of: \nSelect and explain. \nA. Loa Loa, B. Onchocerca volvulus, C. Brugia malayi, D. Mansonella perstans', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Onchocerca Volvulus(Ref: Harrison, 18th/e, p. 1748; 19th/e, p. 1421)* Subcutaneous itchy nodules over the left illiac crest, Skin scrapings containing microfilaria and adult worms confirms the diagnosis of Onchocerca volvulus.", 'role': 'assistant'}]