A student prepares a buffer solution by dissolving \(0.10\text{ mol}\) of \(\text{CH}_3\text{COOH}\) and \(0.10\text{ mol}\) of \(\text{NaCH}_3\text{COO}\) in distilled water to yield \(1.0\text{ L}\) of solution (for \(\text{CH}_3\text{COOH}\), \(\text{p}K_a = 4.75\)). The initial \(\text{pH}\) of the solution is \(4.75\). If \(0.010\text{ mol}\) of \(\text{HCl}(g)\) is added to the solution with negligible volume change, which of the following best predicts and explains the resulting \(\text{pH}\) of the solution?