In which choice are the sodium halides listed in order of increasing lattice energy?

To put it another way, lattice energy is the energy that causes the ionic solid to break down into its component cations and anion.

The energy generated during the production of sodium chloride, for instance, from sodium ions and chloride ions in a gaseous state, is $787.3 \mathrm{kJ}/\mathrm{mol}$ and is referred to as the lattice energy of sodium chloride.

The breakdown of this ionic solid into its individual ions will take the same amount of energy.

Ionic radius and lattice energy often rise as we descend in a group. Lattice energy does, however, rise when ion charge increases in a period from left to right.

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

Consequently, the proper order of lattice energy is $\mathrm{NaBr}<\mathrm{NaCl}<\mathrm{NaF}$.

Hence, option B is correct.