Answer:
A) Scientists use models of natural systems because these systems are often too large, too small, or too complex to study directly
Step-by-step explanation:
Natural systems are those that were not created by humans (non-artificial ones), ie of non-human origin (natural). They are natural systems: The solar system, Biosphere, Ecosystem. Set of elements that interact with each other, making exchanges and influencing each other. These systems are huge, or too smal, with many different components, complex and difficult to evaluate, so when scientists want to study this type of system, it is necessary to make models that represent the system as faithfully as possible.