The oxides $\text{BaO}$, $\text{CaO}$, $\text{MgO}$ and $\text{SrO}$ each form alkaline solutions when they are added to water. Which oxide gives the saturated solution with the greatest $\text{pH}$?
- A$\text{BaO(aq)}$
- B$\text{CaO(aq)}$
- C$\text{MgO(aq)}$
- D$\text{SrO(aq)}$