Historian:  Newton developed mathematical concepts and techniques that are fundamental to modern calculus.  Leibniz developed closely analogous concepts and techniques.  It has traditionally been thought that these discoveries were independent.  Researchers have, however, recently discovered notes of Leibniz’ that discuss one of Newton’s books on mathematics.  Several scholars have argued that since the book includes a presentation of Newton’s calculus concepts and techniques, and since the notes were written before Leibniz’ own development of calculus concepts and techniques, it is virtually certain that the traditional view is false.  A more cautious conclusion than this is called for, however.  Leibniz’ notes are limited to early sections of Newton’s book, sections that precede the ones in which Newton’s calculus concepts and techniques are presented.

In the historian’s reasoning, the two boldfaced portions play which of the following roles?

1. The first provides evidence in support of the overall position that the historian defends; the second is evidence that has been used to support an opposing position.
2. The first provides evidence in support of the overall position that the historian defends; the second is that position.
3. The first provides evidence in support of an intermediate conclusion that is drawn to provide support for the overall position that the historian defends; the second provides evidence against that intermediate conclusion.
4. The first is evidence that has been used to support a conclusion that the historian criticizes; the second is evidence offered in support of the historian’s own position.
5. The first is evidence that has been used to support a conclusion that the historian criticizes; the second is further information that substantiates that evidence.

发现下载的GWD和大家的编号不太一样，找不到这个题目的旧贴，只好发新贴问问

答案说是D，看不明白

我觉得两个黑体部分都是evidence，因为都是陈述事实，但是the historian’s own position到底是什么呢？第一部分黑体也反驳了传统的观点，怎么还说The first is evidence that has been used to support a conclusion that the historian criticizes呢？

恳请nn指教，题目做多了发现逻辑分析能力有点混乱了