To accurately determine how the last paragraph contributes to the development of the ideas in the passage, I would need to see the specific content of the passage and the last paragraph. However, based on the options provided:
- A focuses on explaining studies, which is more about historical context than a direct reinforcement of the main idea.
- B emphasizes the need for adequate sleep, which could be a key point in many passages about sleep.
- C discusses sleep disorders and their prevention, which would add a specific aspect of sleep's importance.
- D addresses the significance of research on sleep's impact, which could help justify the exploration of the topic.
If the last paragraph directly underscores the necessity of sleep for health, then B would be the best choice. If it highlights the significance of examining sleep's impact generally, then D could be more fitting.
Without the specific passage, I can't definitively choose the correct answer. If you have the passage or more context, I could help you identify the best choice.