Ecology focuses on how human activities affect an ecosystem and ways to mitigate resulting issues.

Applied Ecology.

Explanation:

Applied ecology can be defined as the application of ecology in the normal day to day life. The applied ecology considers the application of the science of the ecology to solve the real world problems.

It is also called as environmental technology which focus on the human activities that affects the environment and what steps can be used to reduce the effect of human activities on environment.

the answer would be 3

b.