A body of mass $m$ connected to a massless and unstretchable string goes in a vertical circle of radius $R$ under gravity $g$. The other end of the string is fixed at the center of circle. If velocity at top of circular path is $n\sqrt{gR}$, where $n \geq 1$, then ratio of kinetic energy of the body at bottom to that at top of the circle is:\\
(1) $\frac{n^2}{n^2 + 4}$\\
(2) $\frac{n^2 + 4}{n^2}$\\
(3) $\frac{n+4}{n}$\\
(4) $\frac{n}{n+4}$