The correct answer is D. He was the first person to believe the earth was round.
Explanation
Christopher Columbus was an Italian navigator who discovered America in the XV century when with the help of Spain kingdom of Castilla crossed the Atlantic Ocean and arrived in a Caribbean Island after convincing them that the land was round and by the Atlantic, they could get to India. Nevertheless, he was not the first person who believed that the earth was round, because, from Ancient Greece, some philosophers argued that the earth was round. but, popularity is usually associated with Galileo Galilei with the discovery of the spherical shape of the earth. So, the correct answer is D. He was the first person to believe the earth was round.
