Which of the following substances is a non-electrolyte?

A non-electrolyte is a substance that does not conduct electricity when dissolved in water. It is usually a covalent compound that does not dissociate into ions when dissolved in water. Among the given substances, only C₆H₁₂O₆ (glucose) is a non-electrolyte because it is a covalent compound made up of molecules that do not dissociate into ions in water. The other substances are electrolytes because they either ionize or dissociate into ions in water and conduct electricity. H₂SO₄ and NH₄Cl are strong electrolytes because they dissociate completely into ions in water, while CH₃COOH is a weak electrolyte because it only partially ionizes in water.