Answer: D) III and IV 
Step-by-step explanation: Conductors are substances which can easily conduct electricity through them. The solutions which conducts electricity are called as electrolytic conductors and conduct by production of free ions. 
Thus the substances to be dissolved in water must dissociate to give ions.
Water being strongly bonded through hydrogen bonds do not dissociate and sucrose being a covalent compound do not dissociate into ions.
Salt 
 being ionic compound easily dissociate and hydrochloric acid
 being ionic compound easily dissociate and hydrochloric acid 
 is an acid which dissociates in water to give {[ex]H^+[/tex] ions.
 is an acid which dissociates in water to give {[ex]H^+[/tex] ions.

