90. A student needs a solution buffered at pH 4.30 ([H+] = 5.0×10−5 M). This student can choose from the following weak acidsand their salts to prepare the buffer. Which system will own the best buffering capacity?
(A) Benzoic acid (Ka = 6.4 × 10-5)
(B) Chloroacetic acid (Ka = 1.35 × 10-3)
(C) Propanoic acid (Ka = 1.3 × 10-5)
(D) Hypochlorous acid (Ka = 3.5 × 10-8)