A mass of \[6\times {{10}^{24}}kg\] is to be compressed in a sphere in such a way that the escape velocity from the sphere is \[3\times {{10}^{8}}m\,/s\]. Radius of the sphere should be \[(G=6.67\times {{10}^{-11}}N-{{m}^{2}}/k{{g}^{2}})\] [UPSEAT 2002]

• A. 9 km   
• B.             9 m
• C.             9 cm   
• D.             9 mm