Final answer:
The correct order from most contaminated to least contaminated ecosystems is B) Urban, Terrestrial, Aquatic, as urban areas concentrate pollution from human activities, while aquatic systems are less directly affected.
Step-by-step explanation:
To arrange the categories of ecosystems from most contaminated to least contaminated, we need to consider the human impact on these environments. Urban ecosystems are generally the most contaminated due to the concentration of people, industries, and vehicles, which lead to air and water pollution, and solid waste generation. Terrestrial ecosystems vary in levels of contamination based on human activities such as agriculture, manufacturing and deforestation, making them generally less contaminated than urban areas but more so than naturally occurring aquatic systems. Aquatic ecosystems such as oceans and freshwater systems can be contaminated by runoff from terrestrial zones or direct pollution, but on average, they are less influenced by direct human activity than terrestrial and urban ecosystems.
Considering the provided information and general environmental impact, the correct order from most contaminated to least contaminated would likely be: B) Urban, Terrestrial, Aquatic.