Passage Summary: A bookstore owner argues that you should only shop at local independent shops because chain stores are killing off the variety that only independent stores provide.

Conclusion: Consumers ought to purchase books exclusively from independent bookstores rather than from large bookstore chains.

Reasoning: Independent stores offer a broader selection of titles, and because chains threaten the survival of these independent stores, they effectively diminish the total variety of books available to the public.

Analysis: The argument makes a leap from a factual observation about market variety to a moral prescription about where people should spend their money. To justify this, we need a principle that connects the preservation of variety to consumer obligation. Look for an answer that suggests consumers have a duty to avoid supporting businesses that reduce the diversity of products available in a marketplace.