The correct answer is D. To persuade people to agree to the plan
Step-by-step explanation:
In texts, most common purposes include to inform, to persuade, to narrate and to describe, each of these purposes has a different focus and vary according to the intentions of the writer. In the case of Michale as he wants to "encourage the school to adopt a proposed plan for recycling plastic bottles" his purpose is more likely to persuade its audience because he does not only want the people in the school to know about the plan but Michael wants to convince everyone about the plan he designed. Thus, the purpose, in this case, is to persuade people to agree to the plan.