A mass of 5 kg is connected to a spring. The potential energy curve of the simple harmonic motion executed by the system is shown in the figure. A simple pendulum of length 4 m has the same period of oscillation as the spring system. What is the value of acceleration due to gravity on the planet where these experiments are performed?

A

4 m s$$^{-2}$$

B

8 m s$$^{-2}$$

C

5 m s$$^{-2}$$

D

10 m s$$^{-2}$$