The average period of pendulum clock is found to be 1.2s at sea level. The period of the same pendulum on a mountain top is found to be 1.18s. If the acceleration due to gravity at sea level is 9.790m/s ² , what is the acceleration due to gravity at the mountain top?

a. 9.82m/s ²

b. 10.21 m/s ²

c. 10.12 m/s ²

d. 8.93 m/s ²