Which set of compounds is arranged in order of increasing

Solution 6SAQ Step 1 of 2 The lattice energy is the energy associated with the formation of a crystalline lattice of alternating cations and anions from the gaseous ions. Its value depends by ion dimensions because two ions cannot stay to close one to each other without raising the lattice energy. Lattice energies become less exothermic (less negative) with increasing ionic radius. Lattice energies become more exothermic (more negative) with increasing magnitude of ionic charge We know that ionic radii increases as we move down to a column and decreases as we move from the left to the right along a period. We are going to demonstrate that the correct answer is for letter a)