The sellers of products to consumers in outlets (or 'shops').

• A. Mail order
• B. Retailers
• C. Intermediaries
• D. A two-level distribution channel

Answer: (B)

The key idea here is identifying who directly sells to consumers in physical shops. Those sellers are retailers—the businesses that stock, display, and sell products to end users in outlets or stores. Mail order refers to selling by catalog or mail rather than in-store, so it isn’t about shops. Intermediaries is a broad term for middlemen in the distribution chain (like wholesalers or agents) and doesn’t specify the final in-store seller. A two-level distribution channel describes a structure with two intermediary steps (for example producer → wholesaler → retailer → consumer) rather than naming the type of seller in outlets. Therefore, the best fit is retailers.