Which of the following best describes the function of the highlighted sentence in the context of the passage as a whole? A. It points out a flaw in a theory discussed earlier in the passage. B. It demonstrates the need for additional research on a phenomenon mentioned earlier in the passage. C. It underscores the importance of a trait mentioned earlier in the passage. D. It supports an assertion made earlier in the passage. E. It questions the evidence for a tradition mentioned earlier in the passage.