In the reaction of 1-X-2,4-dinitrobenzene with sodium methoxide in methanol, the order of reactivity for X = F, Cl, Br, I (same conditions) is such that the most reactive substrate is

1. Athe fluoro compound, because the strongly electronegative $\mathrm{F}$ stabilises the Meisenheimer intermediate formed in the rate-determining addition step
2. Bthe chloro compound, because $\mathrm{Cl}$ is the best compromise between bond strength and size
3. Cthe iodo compound, because $\mathrm{C}-\mathrm{I}$ is the weakest bond
4. Dall four react at the same rate because the leaving group is not involved at all