A question about the history of college entrance examination and the land.

The most important thing about Columbus's voyage was that he realized that the earth was round, so he could also reach India westward. At that time, people knew the existence of Asia, Africa, Latin America and Europe, but they didn't know the existence of America, so Columbus always thought he had arrived in India after arriving in America. The two maps on the CD clearly indicate North and South America, which must be the map after Columbus. A's map is a plan, not a star map. Choose b, it's a star map. At the same time, there are only Asia, Africa and Europe, and no America conforms to the cognition at that time.