The Lattice Enthalpy of Calcium Oxide Is the Energy Change $\rightarrow$

The lattice enthalpy of calcium oxide is the energy change for the reaction

A) CaO(s) $\rightarrow$ Ca(g) + O(g)
B) CaO(s) $\rightarrow$ Ca(g) + ½O₂(g)
C) Ca(g) + O(g) $\rightarrow$ CaO(g)
D) CaO(s) $\rightarrow$ Ca²⁺(g) + O^2-(g)
E) Ca(s) + ½O₂(g) $\rightarrow$ CaO(s)