sunlight and nutrient availability
D is the correct answer :)
Answer:
Sewage, oil, pesticides and fertilizers affect water quality.
Explanation:
There are three types of pollution i. e. air pollution, soil pollution and water pollution. Smoke and smog are present in the air is the example of air pollution, waste product, using of pesticide and industrial dumping are the example of soil pollution and chemicals in water due to runoff of fertilizer, sewage and oil are the main agents of water pollution. These three types of pollution adversely affected the water quality. Water quality will be affected when the fertilizer or pesticides runoff from land to water bodies. Sewage and oil also lowers the quality of water.
Answer take one piece of the squirrels diet away and see if anything has changed, if not give it that part back and take something else. repeat till change happens if nothing happens then change hypothesis