If \( R \) is the radius of the earth and the acceleration due to gravity on the surface of earth is \( g = \pi^{2}\, \mathrm{m/s^{2}} \), then the length of the second's pendulum at a height \( h = 2R \) from the surface of earth will be:
\( \frac{4}{9}\, \mathrm{m} \)
\( \frac{2}{9}\, \mathrm{m} \)
\( \frac{1}{9}\, \mathrm{m} \)
\( \frac{8}{9}\, \mathrm{m} \)