Answer:
D. How we use natural resources and how our actions alter the environment.
Step-by-step explanation:
The Environmental studies is the branch of science which deals and studies about the interaction of human being and the other biotic components present in the earth which is collectively called as nature.
The environmental Scientist study about how the available natural resource is utilized by the human race and the advantages and disadvantages caused to the environment due to it.
For example, the usage of available fossil fuels such as coal and petroleum is studied and their usage consequences are updated by them.