Which statement accounts for the observation that magnesium hydroxide dissolves in aqueous ammonium chloride, but does not dissolve in aqueous sodium chloride?
- AThe ionic radius of the $\text{NH}_4^+$ ion is similar to that of $\text{Mg}^{2+}$ but not that of $\text{Na}^+$.
- B$\text{NH}_4\text{Cl}$ dissociates less fully than $\text{NaCl}$.
- CThe $\text{Na}^+$ and $\text{Mg}^{2+}$ ions are isoelectronic.
- DThe $\text{NH}_4^+$ ion can donate a proton.