Answer: c. A sugar molecule does not break apart in solution, so there is no charge carrier.
Sugar molecules is not a ionic compound so it does not ionize, i.e. it does not brake apart in solution. In a solution the ions are the particles that are able to carry the charge. Hithout charge carriers, electricity is not conducted. That is why a sugar solution does not conduct electricity, and why a sodium chloride solution (so a other ionic salts) does conduct electricity.