Explanation

(c)
In $p$-nitrobenzoyl chloride, $- NO_{2}$ group has a $–I$ and $–R$ -effect and this is greater from the $p$-position than from $m$-or $o$-positions. Thus, $- NO_{2}$ group reduces the electron density at the carbon atom attached to $–Cl$ atom and facilitate its releasing and hydrolysis of benzoyl chloride
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Whereas, $CH_{3}O$ -group has a strong $+ R$ –effect and a weak $–I$-effect. At $p$-position $CH_{3}O$-group exerts its strong $+ R$ effect. As a result, electron density at C-atom attached to $–Cl$ atom increases and the cleavage of $C - Cl$ bond becomes difficult.
Hence, the order of reactivity of hydrolysis of acid chlorides :
$p - O_{2}NC_{6}H_{4}COCl > PhCOCl > p - CH_{3}OC_{6}H_{4}COCl$