The correct answer is D. Acetic acid.
Aqueous solutions of acids, bases, and salts are good conductors of electricity. This is because these solutions contain ions, which are charged particles that can move freely through the solution. When an electric current is passed through an aqueous solution, the ions are attracted to the oppositely charged electrode and flow towards it. This flow of ions is what allows the electricity to conduct through the solution.
Ammonium acetate, glucose, and ammonia are all nonelectrolytes. This means that they do not dissolve in water to form ions. As a result, aqueous solutions of these substances do not conduct electricity.
Acetic acid is a weak acid. This means that it only partially dissociates in water to form ions. However, even though the dissociation is incomplete, there are still enough ions present in an aqueous solution of acetic acid to allow it to conduct electricity.
Therefore, the correct answer is D. Acetic acid.