Please help me PLEASE

How are systems affected by change(s)?

How can one system be considered a component of another system?

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

correct answer: understand the different control methods available

integrated pest management is an strategy that is based on the ecosystem and try to prevent the pest and the damage caused by them by applying combination of technique like habitat manipulation, biological control and use of resistant varieties.

the main aim of the integrated pest management is not to completely eliminate the pest but to strengthen the ecosystem so that conditions are favorable for plants and unfavorable for pests.