题目选项分析

Art Historian: Recently, computer analysis has revealed that a few of a famous Flemish artist's works are forgeries, and are actually the work of noted forger Elmyr de Hory. While such a development may emit violent reverberations through the art world, even those museums that have a wealth of the Flemish artists in their collections should not be overly concerned. Hundreds of this Flemish artist's works were tested to determine whether they were forgeries, yet only a slim few turned out to be actual forgeries. Thus, the master's reputation as one of the greatest artists humanity has ever produced will surely remain undiminished.

Which of the following, if true, casts the most doubt on the art historian's conclusion?

【选项】Many of the Flemish artist's well-known portraits are in the collection of private owners and were therefore not subjected to computer analysis.