$\text{NaOH(aq)}$ is introduced separately to samples of magnesium chloride solution and barium chloride solution. $\text{H}_2\text{SO}_4\text{(aq)}$ is then added drop by drop to each reaction mixture until it is in excess. What is seen at the end of this sequence of reactions?
- A$\text{MgCl}_2\text{(aq)}$: colourless solution only; $\text{BaCl}_2\text{(aq)}$: colourless solution only
- B$\text{MgCl}_2\text{(aq)}$: colourless solution only; $\text{BaCl}_2\text{(aq)}$: white precipitate
- C$\text{MgCl}_2\text{(aq)}$: white precipitate; $\text{BaCl}_2\text{(aq)}$: colourless solution only
- D$\text{MgCl}_2\text{(aq)}$: white precipitate; $\text{BaCl}_2\text{(aq)}$: white precipitate