You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Recycling is important to the environment because it
(A) is a good way to earn money. (B) produces more carbon dioxide for plants. (C) decreases the amount of natural resources. (D) is a way of conserving nonrenewable resources.
D