Imagine a light planet revolving around a very massive star in a circular orbit of radius R with a period of revolution T. If the gravitational force of attraction between planet and star is proportional to \[{{R}^{-\frac{5}{2}}}\], then \[{{T}^{2}}\] is proportional to [IIT 1989; RPMT 1997]

• A.             \[{{R}^{3}}\]
• B.                      \[{{R}^{7/2}}\]
• C.             \[{{R}^{5/2}}\]       
• D.             \[{{R}^{3/2}}\]