How does the circulatory system maintain homeostasis?

The Circulatory System delivers oxygen and nutrients in the blood to the surrounding cells to maintain Homeostasis. The blood in the Circulatory System is needed throughout the body so that other systems work properly. Like for instance the Nervous System has the brain, and the brain needs blood to function.

Iam not sure but to me it with be a or dsorry if i was late! hope this ! : )if you really want me to find out the answer that is correct tell me and i will do more research but the a or d makes sense to me.