See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

COOH   O O H  1 2  1 2   COOH OH   C O O O H H  1 2   1 2   COOH OH O H   C O O O H O H H  1 2   1 2   So, benzoic acid will be least acidic and 2,6-dihydroxy benzoic acid will be most acidic. So. option (A) is correct.