The statement that best explains how multiple organ systems work together to achieve homeostasis during exercise is:
"The respiratory system increases oxygen intake, the circulatory system transports oxygen to muscles, and the excretory system removes carbon dioxide."
This statement correctly describes the roles of different organ systems in regulating internal conditions during physical activity. The respiratory system facilitates the intake of oxygen, which is essential for muscle function, while the circulatory system ensures that this oxygen is delivered to the muscles. Additionally, the excretory system plays a vital role in removing carbon dioxide, a waste product of metabolism, to maintain homeostasis.