Answer:
To introduce one source of the settlers' fears
Explanation:
The information about the earlier colony of Sir Walter Raleigh was meant to introduce a factor that must have created doubts and fears in the minds of the new colonists. The settlers sent by Sir Walter Raleigh had disappeared mysteriously.
So, the settlers must have wondered what could have happened to them, and if the circumstances behind their disappearance might have affected them as well. So that was one source of the settlers' fears.
Answer: When you figure out the main idea, you can then see how the author addresses it. If they have a bias opinion against, or for it, you can note their ton when the speak about it. Knowing the main idea, can help show why the author is writing about it, and how they feel about it as well.
Explanation: Hope it helps :)
The answer would be D correct me if i'm wrong.