An experiment test of the Law of conservation of Mass is illustrated in the diagram. In practice, the flask is weighed before and after reaction between solutions X and Y. Which of the following pairs of solutions will be unsuitable for the experiments

• A.X = hydrochloric acid; Y = silver nitrate
• B.X = barium chloride; Y = dilute sulphuric acid
• C.X = hydrochloric acid; Y = sodium hydroxide
• D.X = hydrochloric acid; Y = lead nitrate
• E.X = hydrochloric acid; Y = sodium carbonate