Find the ratio of weights of a body at heights \[{}^{R}/{}_{2}\] and \[{}^{R}/{}_{3}\]from the surface of the earth (where R is the radius of the earth)

• A.  \[\frac{3}{2}\]                                  
• B.  \[\frac{2}{3}\]
• C.  \[\frac{64}{81}\]                             
• D.  \[\frac{1}{2}\]