Both are large, rocky bodies in space but asteroids tend to stay in the asteroid belt, while meteoroids are a bit smaller and more active.
The answer to the question is C.
Answer: The oxygen content at the source of the streams or rivers is higher as compared to the mouth of the river. Consequently, the organisms which require more oxygen tend to find at the source of the rivers whereas the organisms which require less oxygen tend to find at the mouth of the river.
Explanation: