Answer: B. Measure the energy of the food, the dolphin, and the aquarium before feeding and after feeding. Determine the difference to show that energy has changed forms.
The law of conservation of energy is a law of science which states that energy neither be created nor be destroyed, but it only changes from one form to another form. In the given example the energy from the food is transfered to the dolphin. Therefore, the energy changed from one form to another form that is food to dolphin.
Hence, measure the energy of the food, the dolphin, and the aquarium before feeding and after feeding and determining the difference to show that energy has changed forms can be useful method for demonstrating the law of conservation of energy.