Passage Summary: In the 90s, big bookstores started popping up and best-sellers started flying off the shelves, while more serious literary books didn't do so well. The author blames this on the fact that these big stores give huge discounts on the hits, making everything else look too expensive.

Conclusion: The emergence of book megastores was the primary cause for the decline in sales of literary, non-commercial books.

Reasoning: During the decade megastores rose to prominence, best-seller market share doubled while megastores offered their steepest discounts on those specific titles, which discouraged the purchase of other hardcover books.

Analysis: This argument relies on a correlation-to-causation jump, assuming that because megastores and best-seller dominance happened at the same time, the former caused the latter. To weaken this, look for an answer that suggests a different reason why literary book sales dropped. Perhaps the tastes of the reading public shifted naturally, or maybe independent stores—which usually champion literary fiction—were closing for reasons unrelated to megastore pricing. Any alternative explanation for the shift in sales data will undermine the author's finger-pointing at the megastores.