A gaseous diatomic molecule $\mathrm{XY}$ has a bond length of $160\mathrm{pm}$ and its bond is $18\%$ ionic. Taking percent ionic character $=100\times {\mu }_{obs}/(ed)$ with $e=1.6\times 10^{-19}\mathrm{C}$ and $1\mathrm{D}=3.336\times 10^{-30}\mathrm{C}\mathrm{m}$, the observed dipole moment is closest to

1. A$2.76\mathrm{D}$
2. B$7.67\mathrm{D}$
3. C$0.14\mathrm{D}$
4. D$1.38\mathrm{D}$