Changing the Ecosystem

A food chain is a series of links between plants and animals. It starts with a plant. The next part of the link is a plant eater. When the prairie plants started to die or be replaced with houses and roads, the animals that depended on them lost their food source. So while the farmers produced more food for people, they broke the animals’ food chain and the animals died or had to move. This was a great mistake. We are paying for that mistake today. And, unfortunately, people still keep making that mistake. They keep breaking the food chains.

A food chain is part of a bigger system called a food web. That web links the living things in an ecosystem. The herbivores in that system depend on the plants. If the plants are removed, the herbivores cannot survive. Then the carnivores, the animals that eat other animals, lose their food, too. Remove just one kind of plant from an environment and you disrupt the food web. Plow up the land and you destroy the whole system. The problem was there were more and more people and less and less natural habitats.

How does the structure of the passage above impact the meaning of the text?

A) The author presents a list of problems about the ecosystem followed by solutions to fix them.
B) The author provides details about the ecosystem in the order that they occurred.
C) The author compares and contrasts parts of the ecosystem to show how it is changing.
D) The author lists causes of changes in the ecosystem and their effects on the environment.