Working down mate, my best answer would be carbon monoxide, but I'm not studying exactly what you are. All those answers are logical except ozone.
Explanation:
In a freshwater aquatic ecosystem like a pond, the organisms in the food chain include algae, small animals, insects and their larvae, small fish, big fish and a fish-eating bird or animal
pls mark brainliest
The answer you are looking for is false
I’m not sure but I think A
