The author refers to the textbook in lines 22-26. To paraphrase, they tell us that while old textbooks did not focus on women folk performers, this new textbook spends quite some time on them. This supports the assertion above that folklore scholars are spending more time on female folklore performers.
This is a pretty good match for E. While the term critical is a bit odd, as this is a book by academics, it still matches our understanding of why the author references the textbook.
C refers to the assertion that scholarship about women focuses on repetriore rather than the performers. However, we are never told this is true of the textbook. In fact, we are told that this textbook DOES in fact focus on women performers, in lines 25-26.
