If the bond dissociation energies of `XY`,`X_(2)` and `Y_(2)` are in the ratio of `1:1:0.5` and `DeltaH_(f)` for the formation of `Xy` is `-200 KJ//mol`. The bond dissociation energy of `X_(2)` will be `:-`
A. `100 KJ//mol`
B. `400 KJ//mol`
C. `600 KJ//mol`
D. `800 KJ//mol`