<prompt> The organism most commonly causing genital filariasis in most part of Bihar and eastern U.P. is-Wuchereria bancroftiBrugia malayiOnchocerca volvulusDirofilaria  <response>: The nocturnal periodic strains of Wuchereria bancrofti is most wide spread in India.Mainly along seacoast and riverbanks.Heavily infected areas Uttar Pradesh, Bihar, Andhra Pradesh, Orissa, Tamil Nadu, Kerala and Gujarat 