Which sentence best expresses the central idea of a paragraph about recycling's impact on the environment?

• A. Recycling reduces resource waste and helps protect nature
• B. Recycling is optional and not helpful
• C. Recycling has no environmental impact
• D. Recycling should be banned

Answer: (B)

The main idea being tested is that recycling has a positive impact on the environment. The sentence that best expresses this central idea says that recycling reduces resource waste and helps protect nature. That option conveys the overall message of the paragraph by linking the action (recycling) to its big-picture effects (conserving resources and safeguarding ecosystems). The other statements conflict with that positive view: claiming recycling is optional and not helpful, saying it has no environmental impact, or suggesting it should be banned, all go against the idea that recycling benefits the environment.