A student compares the molar solubility of excess solid \(\text{Mg(OH)}_2\) in pure water with its molar solubility in a pH-controlled acidic solution at the same temperature. The acidic solution does not initially contain \(\text{Mg}^{2+}\). The relevant equilibria are

\(\text{Mg(OH)}_2\text{(s)} \rightleftharpoons \text{Mg}^{2+}\text{(aq)} + 2\text{OH}^{-}\text{(aq)}\)

\(\text{H}_3\text{O}^{+}\text{(aq)} + \text{OH}^{-}\text{(aq)} \rightleftharpoons 2\text{H}_2\text{O(l)}\), which is strongly product-favored.

Which of the following correctly predicts and explains how the molar solubility of \(\text{Mg(OH)}_2\) in the acidic solution compares with its molar solubility in pure water?