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': 'A child from Bihar comes with fever. Blood examination shows sheathed microfilaria with nuclei up to tail tip. The diagnosis is - \nSelect and explain. \nA. B. Malayi, B. W. Bancrofri, C. Loa loa, D. Oncocerca volvulous', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mf malayi Smaller Kinky with secondary curves Twice as long as broad Double stylet present Two distinct nuclei,one terminal and the other subterminal (refer pgno:170 baveja 3 rd edition)', 'role': 'assistant'}]