Answer: Option 'c' is correct.
Explanation:
Potential energy is the energy which is held by an object because of its position with respect to other object.
And the higher the object , the greater amount of potential energy it will have.
So, among the options, Hanging 20 m from the ground is the highest height of an object with respect to other object i.e. ground.
So, Hanging 20 m from the ground have greater amount of potential energy.
Hence, Option 'c' is correct.