Historians have commonly believed that paint used before the year 1500 did not contain copper. However, lab techniques have shown that copper is present in the paint of both the Mona Lisa painted by Leonardo da Vinci (1452-1519), a widely-renowned and timeless piece that is one of the most valuable pieces in the Louvre today, and in that of another painting known as the Sine Nomine, also from the same time period, whose painter is unknown—but not found in the paint of any other Renaissance painting analyzed. This is strong evidence that the Sine Nomine was painted by da Vinci, as well as evidence that the presence of copper in the paint of a recently resurfaced map by Fra Mauro, ostensibly from the year 1450, cannot be used as an argument against the map's authenticity.

The reasoning in the passage is vulnerable to criticism on the grounds that:

A) both the Sine Nomine and the Fra Mauro 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
B) it is unreasonable to suppose that determination of the date and location of an art piece’s painting or drawing can be made solely on the basis of the presence or absence of a single element in the paint used in the document
C) the results of the analysis are interpreted as indicating that the use of copper as an ingredient in fifteenth-century paint both was, and was not, extremely restricted
D) the discovery of copper in the paint of the Fra Mauro Map must have occurred before copper was discovered in the paint of the Sine Nomine and Mona Lisa
E)if the technology that makes it possible to detect copper in paint has only recently become available, it is unlikely that cartographers or artists in the fifteenth century would know whether their paint contained copper or not