Anthropologist: In an experiment, two groups of undergraduates were taught how to create one of the types of stone tools that the Neanderthals made in prehistoric times. One group was taught using both demonstrations and elaborate verbal explanations, whereas the other group learned by silent example alone. The two groups showed a significant difference neither in the speed with which they acquired the toolmaking skills nor in the level of proficiency they reached. This shows that Neanderthals could just as well have created their sophisticated tools even if they had no language
Which one of the following, if true, most weakens the anthropologist's argument?
(A) Apart from the sophistication of their stone tools, there is a great deal of evidence suggesting that Neanderthals possessed some form of language.
(B) The students who were taught with verbal explanations were allowed to discuss the toolmaking techniques among themselves, whereas the students who learned by silent example were not.
(C) The tools that the undergraduates were taught to make were much simpler and easier to make than most types of tools created by Neanderthals.
(D) The instructor who taught the group of students who learned by silent example alone was much less proficient at making the stone tools than was the instructor who taught the other group of students.
(E) The tools created by Neanderthals were much less sophisticated than the tools created by anatomically modem humans who almost certainly possessed language and lived at the same time as the Neanderthals.