单选题 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 or 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 Vinland 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、 (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.

【正确答案】 A

【答案解析】[解析] 从本题的论证中可以看出在15世纪时使用钛元素作为油墨的一种成份非常地有限；而另一方面，在15世纪时，只有当含有钛的油墨被广泛使用时，被号称为15世纪的Vinland地图的墨迹中含有碳元素才不能作为怀疑该画的真实性的一个原因。由以上分析可以得出本题辩论中的自相矛盾，即15世纪使用钛作为墨水的一种成份，即非常地有限，又非常地普遍，因此(A)是正确答案；(B)是无关选项；(C)、(D)和(E)三个选项都不能从短文中推出。