The bond dissociation energies of $$X_{2},Y_{2}$$ and XY are in the ratio of 1:0.5:1. $$\triangle H$$ for the formation of XY is — 200 kJ $$mol^{-1}$$ The bond dissociation of energy $$X_{2}$$ will be

A

400 kJ $$mol^{-1}$$

B

800 kJ $$mol^{-1}$$

C

100 kJ $$mol^{-1}$$

D

200 kJ $$mol^{-1}$$