Which type of system is unaffected by external environmental factors?

A closed system is defined as one that does not interact with its external environment. This characteristic means that external environmental factors have no impact on the operations, processes, or outputs of a closed system. In a closed system, the internal environment is controlled and self-contained, isolating it from outside influences such as changes in market demand, regulatory policies, or social factors. This can help establish stable operations, but it may limit adaptability and innovation, as the system does not adapt to new information or changes happening outside its boundaries.

In contrast, open systems actively engage with their environments, which can significantly shape their functions and output. Complex systems consist of multiple interconnected components that can influence one another, and dynamic systems highlight the fluidity and changeability over time due to external interactions. Therefore, the nature of being unaffected by external factors distinctly categorizes closed systems, making them the correct answer to the question.