Conductive deafness means the disease process leading to deafness is limited to external ear tympanic membrane, middle ear including the footplate of stapes. Bilateral conductive deafness rules out meniere’s disease (as it presents with SNHL). Amongst the remaining three options, positive family history is seen mainly in case of otosclerosis (Otospongiosis), so it is our answer. Ref. Dhingra 6/e, p 30, 87