A student receives a picture of a savanna ecosystem with an elephant, a tree, and grass shown.



How are gases exchanged among the three organisms present in the ecosystem?


A. The grass and the tree produce carbon dioxide for use by the elephant, and the elephant exhales oxygen for use by the grass and the tree.

B. The grass and the tree produce oxygen for use by the elephant, and the elephant exhales nitrogen for use by the grass and the tree.

C. The grass and the tree produce nitrogen for use by the elephant, and the elephant exhales carbon dioxide for use by the grass and the tree.

D. The grass and the tree produce oxygen for use by the elephant, and the elephant exhales carbon dioxide for use by the grass and the tree.