A seconds pendulum is shifted from a place where g = 9.8 m/s² to another place where g = 9.78 m/s². To keep period of oscillation constant its length should be

• A

  $\text{ decreased by }\frac{2}{{\mathrm{\pi }}^2} \mathrm{cm}$

• B

  $\text{ increased by }\frac{2}{{\mathrm{\pi }}^2} \mathrm{cm}$

• C

  $\text{ increased by }\frac{2}{\mathrm{\pi }}\mathrm{cm}$

• D

  $\text{ decreased by }\frac{2}{\mathrm{\pi }}\mathrm{cm}$