Explain how demographic data can assist policy makers in places like Paris, France, Ireland, and Eastern Europe

Ithink the answer to that would be b):

The saharan africa is desert not forest

Answer is b)eutrophication occurs when excess nutrients are present in aquatic ecosystems, resulting in the increased production of plant life and the subsequent decrease in the oxygen levels of the watereutrophication occurs when there are excess nutrients in a body of water. this results in plants having more food and reproducing  more, sometimes leading to more aquatic animal life as well. ultimately, this can reduce the oxygen level in the ecosystem.