A mass falls from a height $h$ and its time of fall is recorded as $t$ in terms of time period $T$ of a simple pendulum. On the surface of the earth, it is found that $t=2T$. The entire setup is taken on the surface of another planet whose mass is half of that of the Earth and whose radius is the same. The same experiment is repeated and corresponding times are noted as $t^{\prime }$ and $T^{\prime }$. Then we can say:

1. A
   $t^{\prime }=\sqrt{2}T$
2. B
   $t^{\prime }>2T^{\prime }$
3. C
   $t^{\prime }<2T^{\prime }$
4. D
   $t^{\prime }=2T^{\prime }$