参考答案：D

解析：[听力原文]The orthodox explanation of where Columbus first landed was carved in textbook stone more than 40 years ago by the dean of Columbus historians, Samuel Elliot Morrison. Morrison declared incontrovertible the evidence that Columbus first set foot on Watling Island in the eastern Bahamas. But if the question were closed for Professor Morrison, now dead, it was not for numerous other people on nautical history.

[分析]： 观点态度的找寻和判断。 原文首先提出历史学家Samuel Elliot Morrison 已对Columbus 在新大陆何地登陆定论，但讲话者却认为it was not for numerous other people on nautical history即研究航海史的其他学者们却不这样认为。由此可见，选项D的内容与原文相符，因此该项为正确答案。[解题关键] 掌握信号词的用法。原文中讲话者使用But表明其后内容为自己的观点，是全段的中心内容。