A simple pendulum doing small oscillations at a place R height above earth surface has time period of T_1=4 s. T_2 would be it's time period if it is…

A simple pendulum doing small oscillations at a place R height above earth surface has time period of $\displaystyle \mathrm{T}_1=4 \mathrm{~s} . \mathrm{T}_2$ would be it's time period if it is brought to a point which is at a height $\displaystyle 2$ R from earth surface. Choose the correct relation [R = radius of earth]: