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
The organism most commonly causing genital filariasis in most part of Bihar and easteran U.P. is: 
Select and explain. 
A. Wuchereria bancrofti, B. Brugia malayi, C. Onchocerca volvulus, D. Dirofilaria
A: Wuchereria bancrofti
Answer: A: Wuchereria bancrofti 
Explanation: Ans. (a)The organism most commonly causing genital filariasis in most part of Bihar and easteran U.P. is Wuchereria bancrofti. It causes lymphangitis, lymphadenitis, filarial fever, hydrocele, elephantiasis.B. malayi causes lymphangitis and elephantiasis. It is characterized by absence of chyluria and rarity of scrotal swellingO. volvulus causes formation of subcutaneous fibrous nodules and ocular lesionsDirofilaria rarely causes human zoonosis.