Which equation represents the bond enthalpy for the H–Br bond in hydrogen bromide?

A.     ${\text{HBr(g)}} \to {\text{H(g)}} + {\text{Br(g)}}$

B.     ${\text{HBr(g)}} \to {\text{H(g)}} + {\text{Br(l)}}$

C.     ${\text{HBr(g)}} \to {\text{H(g)}} + \frac{1}{2}{\text{B}}{{\text{r}}_2}({\text{l)}}$

D.     ${\text{HBr(g)}} \to {\text{H(g)}} + \frac{1}{2}{\text{B}}{{\text{r}}_2}({\text{g)}}$

A