Final answer:
Pouring water out of a bucket or moving it to the ground decreases the potential energy of the bucket as both actions reduce mass or height, which are factors in calculating potential energy (B).
Step-by-step explanation:
By pouring water out of a bucket or moving a bucket to the ground, you decrease the potential energy of a bucket full of water sitting on a bench. The potential energy of an object is the energy that is stored in it due to its position or height. When the water is poured out, the mass of the bucket decreases, thus reducing the potential energy.
Similarly, moving a bucket to the ground decreases its height relative to the bench, which again reduces the potential energy since potential energy is calculated based on the height of an object in a gravitational field.