It specifies what exactly the variations are of whatever population is being examined.
The second one changes in the amount of atmospheric gases because it think it might effect everyone including plants and animals because will all breath the same air rather than a mountain building it might affect the animals that like there.
Quantitative data because quantitative uses numbers.
Answer:
A. An increase in nutrients
Explanation:
By definition, eutrophication is excessive richness of nutrients in a lake or body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.
