What is the main function of the circulatory system in multicellular organisms?

a.
to bring oxygen into the lung

b.
to put carbon dioxide into all blood vessels

c.
to expel waste products from the body

d.
to transport materials throughout the body

I believe the answer would be D to transport materials throughout the body

D. To transport materials throughout the body

Explanation:

Took the quiz and got it right.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

carbon

explanation: