Answer:
C or the third answer choice
Explanation:
If algae excessively grows on the tops of the water, it can block sunlight. That will make the underwater plants die, and the animals that eat those underwater plants will slowly have less to eat if they can't adapt quickly enough. When the algae dies, it takes oxygen with it. If it take all of the oxygen in the water, that whole ecosystem could potentially die as well.
Fartttttttttssssssssssssss
A. Because mostly because of DNA and the region. But for me the answer is A but might be D too so make sure. Sorry for choices