The lattice energy $\mathrm{NaF}, \mathrm{NaCl}, \mathrm{NaBr}, \mathrm{NaI}$ follow the order

Overall as we go down in a group, ionic radius increases and lattice energy decreases. However, in a period from left to right as the charge on the ion increases, lattice energy increases.

$\mathrm{Lattice} \mathrm{energy} \propto \frac{\mathrm{Charge} \mathrm{on} \mathrm{ion}}{\mathrm{size} \mathrm{of} \mathrm{the} \mathrm{ion}}$

Correct order of lattice energy is $\mathrm{NaI}>\mathrm{NaBr}>\mathrm{NaCl}>\mathrm{NaF}$.

Therefore, the correct option is (B).