A diatomic molecule is made of two masses \[{{m}_{1}}\] and \[{{m}_{2}}\] which are separated by a distance r. If we calculate its rotational energy by applying Bohr's rule of angular momentum quantization, its energy will be given by: (n is an integer)

• A.  \[\frac{{{\left( {{m}_{1}}+{{m}_{2}} \right)}^{2}}{{n}^{2}}{{h}^{2}}}{2m_{1}^{2}m_{2}^{2}{{r}^{2}}}\]
• B.  \[\frac{{{n}^{2}}{{h}^{2}}}{2\left( {{m}_{1}}+{{m}_{2}} \right){{r}^{2}}}\]
• C.  \[\frac{2{{n}^{2}}{{h}^{2}}}{\left( {{m}_{1}}+{{m}_{2}} \right){{r}^{2}}}\]        
• D.  \[\frac{\left( {{m}_{1}}+{{m}_{2}} \right){{n}^{2}}{{h}^{2}}}{2{{m}_{1}}{{m}_{2}}{{r}^{2}}}\]