Final answer:
The statement that best describes energy in a system is D) Energy cannot be created or destroyed, only transferred or converted.
Step-by-step explanation:
D) Energy cannot be created or destroyed, only transferred or converted.
The statement that best describes energy in a system is D) Energy cannot be created or destroyed, only transferred or converted. This statement is known as the law of conservation of energy. According to this law, the total amount of energy in a closed system remains constant. While energy can change forms or be transferred between different objects or systems, the total energy of the system remains the same.