2 more lsat to discuss

thanks a lot!!!
Oscar: I have been accused of plagiarizing the work of Ethel Myers in my recent article. But that accusation is unwarranted. Although I admit I used passages from Myers’s book without attribution. Myers gave me permission in private correspondence to do so.
Millie: Myers cannot give you permission to plagiarize. Plagiarism is wrong, not only because it violates author’s rights to their own words, but also because it misleads readers: it is fundamentally a type of lie. A lie is no less a lie if another person agrees to the deception.
6. Millie uses which one of the following argumentative strategies in contesting Oscar’s position?
(A) analyzing plagiarism in a way that undermines Oscar’s position
(B) invoking evidence to show that Oscar did quote Myers’ work without attribution
(C) challenging Oscar’s ability to quote Myers’ work without attribution
(D) citing a theory of rights that prohibits plagiarism and suggesting that Oscar is committed to that theory
(E) showing that Oscar’s admission demonstrates his lack of credibility

Answer is A, but I don't know why D is not correct.

24. Until recently it was thought that ink used before the sixteenth century did not contain titanium. However, a new type of analysis detected titanium in the ink of the famous Bible printed by Johannes Gutenberg and in that of another fifteenth-century Bible known as B-36, though not in the ink of any of numerous other fifteenth-century books analyzed. This finding is of great significance, since it not only strongly supports the hypothesis that B-36 was printed by Gutenberg but also shows that the presence of titanium in the ink of the purportedly fifteenth century Vinland Map can no longer be regarded as a reason for doubting the map’s authenticity.
The reasoning in the passage is vulnerable to criticism on the ground that
(A) the results of the analysis are interpreted as indicating that the use of titanium as an ingredient in fifteenth-century ink both was, and was not, extremely restricted
(B) if the technology that makes it possible to detect titanium in printing ink has only recently become available, it is unlikely that printers ore artists in the fifteenth century would know whether their ink contained titanium or not
(C) it is unreasonable to suppose that determination of the date and location of a document’s printing or drawing can be made solely on the basis of the presence or absence of a single element in the ink used in the document.
(D) both the B-36 Bible and the Binland Map are objects that can be appreciated on their own merits whether or not the precise date of their creation or the identity of the person who made them is known.
(E) the discovery of titanium in the ink of the Vinland Map must have occurred before titanium was discovered in the ink of the Gutenberg Bible and the B-36 Bible .

答案是A，怎么理解？是因为证据并没保证确实15世纪的墨水里有钛（仅发现两个），所以不能justify 地图的问题。？