Solution:
\(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}\) is the strongest acid. In \(m-\mathrm{CH}_{3} \mathrm{OC}_{6} \mathrm{H}_{4} \mathrm{COOH}\) and \(p-\mathrm{CH}_{3} \mathrm{OC}_{6} \mathrm{H}_{4} \mathrm{COOH}\), the \(-\mathrm{OCH}_{3}\) group' being electron donating makes benzoic acid weaker.