Option 1: Copper sulphate - Copper sulphate is capable of conducting electricity. It dissociates into copper ions (Cu2+) and sulphate ions (SO42-) when it is dissolved in water. These ions are charged particles that can move freely in the solution and carry electric current.

Option 2: Sodium chloride - Sodium chloride is capable of conducting electricity. When dissolved in water, sodium chloride dissociates into sodium ions (Na+) and chloride ions (Cl-), which are capable of carrying an electric current.

Option 3: Sugar - Sugar is not capable of conducting electricity. Sugar molecules do not dissociate into ions when dissolved in water. Since ions are required to carry an electric current, the absence of ions in a sugar solution makes it incapable of conducting electricity.

Option 4: Sodium hydroxide - Sodium hydroxide is capable of conducting electricity. When dissolved in water, it dissociates into sodium ions (Na+) and hydroxide ions (OH-), which can carry an electric current.

In summary, the correct answer is option 3: Sugar. Sugar solutions do not contain ions and therefore cannot conduct electricity.