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
Sheathed microfilaria is/are - 
Select and explain. 
A. W. Bancrofti, B. Loa-loa, C. M. Perstans, D. B. Malayi
A: W. Bancrofti
Answer: A: W. Bancrofti 
Explanation: Covered by hyaline sheath The sheath is much longer than the embryo so that microfilaria can move forward and backward with in it . (refer pgno:165 baveja 3 rd edition)