I believe the answer to your question would be young adults who want to stay healthy.
Answer:
The narrator responds to his fear by staying in the room to learn more.
Explanation:
Sometimes when you face your fear, you can rationalize it or find reasoning behind it.
You can use the synonym clue in understanding the meaning of the underlined word. The other word synonymous to it might be more familiar to you so it would be a lot easier. The synonym clue says the word in a simple way.