There appears to be some relationship between population density and the presence of large dead zones. Can you explain why dead zones seem to be more prominent in areas of high population density
Nitrogen and phosphorus runoff from sewage and agricultural activities in high population centers leads to the formation of dead zones.
People in these high population areas have over fished their coastal waters, leading
dead zones
The abundance of cruise ships in these high population centers results in the production of large amounts of pollution, leading to the formation of dead zones.
This is a random correlation and not a result of population centers causing the dead zones

Dead zones can be defined as an area of significant pollution.

Explanation:

Dead zones are associated with waters with low-oxygen content and the organisms suffer from hypoxic conditions. These areas include the waters of oceans, lakes and other types of water bodies.

The dead zones are created due to human activities. The high density population of human kind require space to survive. They use and contaminate the nearby source of water body. The agriculture pollutants contains fertilizers and pesticides which contains nitrogen and phosphorus that runoff into the water body. Also the sewage discharge also increases the nitrogen content in nearby source. Thus makes the water body oxygen deficient.

The large population of human kind may depend on fishery as source of food thus they may create a dead zone in nearby water body by overfishing and depleting the population to a level of zero.

The cruise may introduce oil contaminants in the water body which can reduce the oxygen availability of the water hence, kill the organism and create a dead zone.

correct answer is a. and d.