= Solution
The neutral para-OH <ester> B lies \b[above] the ordinary Hammett line, so an additional accelerating pathway is needed; ordinary resonance donation by OH alone predicts the wrong direction.
The phenoxide B$^-$ lies far \b[below] the line: its strong resonance donation reduces acyl electrophilicity, and an anionic <ester> is less favorable for approach by OH$^-$. A single neutral-substituent $\sigma$ parameter is also a poor description of this charged, strongly conjugated substrate. These deviations should not be forced onto the same straight line.
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