The Lattice Energy of CaF₂ Is the Energy Change for Which

The lattice energy of CaF₂ is the energy change for which one, if any, of the following processes?

A) Ca²⁺(s) + 2F¯(g) $\rightarrow$ CaF₂(g)
B) CaF₂(g) $\rightarrow$ CaF₂(s)
C) Ca(g) + 2F(g) $\rightarrow$ CaF₂(s)
D) CaF₂(aq) $\rightarrow$ CaF₂(s)
E) None of these choices is correct.