When the chemical agent VIANZONE is added to any transparent solution containing sodium chloride, the solution will become cloudy; when the chemical agent VIANZONE is added to a transparent solution containing potassium nitrate, the solution will become cloudy; but the chemical agent VIANZONE will not change the content Solution of benzene. In one experiment, the chemical agent VIANZONE was added to a transparent solution, and the solution remained transparent. Based on the above experiments, it can be inferred which of the following must be true? ? ['A clear solution contains potassium nitrate.', 'Sodium chloride and benzene in a clear solution.', 'The clear solution does not contain benzene.', 'The clear solution does not contain sodium chloride.']