<prompt> Double aoa occurs due toNon development of the right 4th aoic archNon development of the left 4th aoic archNon division of truncus aeriosusPersistence of distal poion of the right dorsal aoa  <response>: Double aoa occurs due to the persistence of distal poion of the right dorsal aoaRef: Inderbir Singh;s Human embryology; Tenth edition; Pg 257 