Answer:
D) thinking that he was in East Asia, but Amerigo Vespucci correctly deduced is the correct answer.
Step-by-step explanation:
Letter A is incorrect since the connector "and" brings the idea of in addition, meaning that Columbus though he was in another place, in addition it was Vespucci correctly deducing that it was a New World.
Option B is also incorrect because the gerund "thinking" is not a problem in the original sentence and in also includes the same connector as in the first one.
Letter C is incorrect because by using instead of, it could be understood that one took the other's place (that Vespucci was in Asia, in example.)
E is also incorrect because it lacks a subject and it could be a little confusing: "...who 'discovered' America, in East Asia according to his thought..."
Letter D is correct since the connector but introduces a new idea, contrasting with the first one and supporting the idea of Columbus mistake.