Which of the Following Shows the Reaction Associated with the Standard

Which of the following shows the reaction associated with the standard heat of formation of a compound?

A) Ca(s) + C(s,graphite) + O₃ (g) $\rightarrow$ CaCO₃ (s)
B) NO₂ (g) + CL₂ (g) $\rightarrow$ 2 NOCl(g)
C) N₂ (g) + 2 H₂ (g) $\rightarrow$ N₂ H₄ (g)
D) 2 H₂ (g) + O₂ (g) $\rightarrow$ 2 H₂O(l)
E) Na⁺(aq) + OH ^- aq) $\rightarrow$ NaOH(s)