The question here is one after a lesson discussing the laws of thermodynamics. Within this lesson, you may find the fallowing passage: "According to the first law, an organism can absorb energy from its environment, or it can give up some of its energy to its surroundings. However, the total energy of the organism and its surroundings is always the same. The organism can't create the energy it needs to live. Instead, it must capture it from the environment. Once it captures energy, the organism can use the energy for its own biological work."
Answer: First Law of Thermodynamics