Answer:
3. Lower the weight.
Explanation:
The time period of a pendulum is given by
[tex]T=2\pi\sqrt{\dfrac{L}{g}}[/tex]
where,
L = Length of pendulum
g = Acceleration due to gravity = 9.81 m/s²
It can be seen from the equation that the time period depends on the length of the pendulum and the acceleration due to gravity of the planet.
The acceleration due to gravity of the planet is constant so the time period is proportional to the length of the pendulum.
[tex]T\propto \sqrt{L}[/tex]
Here, the time period has reduced as the clock runs fast.
So, in order to increase the time period we have to lower the weight.