The acceleration due to gravity at a place is ${\mathrm{\pi }}^2\mathrm{m}\text{}/\text{}{\sec }^2$. Then the time period of a simple pendulum of length one metre is

• A

  $\frac{2}{\mathrm{\pi }}\sec$

• B

  $2\mathrm{\pi }\sec$

• C

  $2\sec$

• D

  $\mathrm{\pi }\sec$