which of the following could explain why the percentage of brown-shelled insects decreased from year 3 to year 4

I feel like you need a picture or graph for someone to answer this question. Being helpful, I'll guess some possible answers.

Nutrient or water shortages

Environment issues

Disease

Explanation:

because , habitat destruction, land use changes, deforestation, intensive agriculture, urbanization, pollution, climate change, introduction of invasive insect species, application of pesticides, mass trapping of insects using pheromones and light traps, pathological problems on

answer; i believe the correct answer is (a)0

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.