Final answer:
The law of conservation of energy states that energy cannot be created or destroyed but only transformed or transferred within an isolated system. Thus, the total energy within a closed system remains constant.
Step-by-step explanation:
The law of conservation of energy states that in any physical or chemical process, energy is neither created nor destroyed. This foundational concept in physics implies that the total amount of energy in an isolated system is constant despite the possibility of energy changing forms or being transferred from one part of the system to another.
Applying this principle, the correct statement from the options given to the student would be that the total amount of energy is constant for a closed system. This is because within such a system, energy can only be transformed from one type to another, such as from potential energy to kinetic energy, or transferred between objects or fields, but the overall energy balance does not change.