The lattice energies of $\mathrm{NaCl}, \mathrm{NaF}, \mathrm{KCl}$ and $\mathrm{RbCl}$ follow the order

• A

  $K \mathrm{Cl} < \mathrm{RbCl} < \mathrm{NaCl} < \mathrm{NaF}$
• B

  $\mathrm{NaF} < \mathrm{NaCl} < \mathrm{KCl} < \mathrm{RbCl}$
• Correct answer
  C

  $\mathrm{RbCl} < \mathrm{KCl} < \mathrm{NaCl} < \mathrm{NaF}$
• D

  $\mathrm{NaCl} < \mathrm{RbCl} < \mathrm{NaF} < \mathrm{KCl}$

Hence, the correct answer is option: 'C'.