We need to find the option that best explains this difference in behavior.
A) Customers regard themselves as doing salespeople a favor by buying from them as opposed to someone else.This would suggest customers see themselves as benefactors in the transaction, which might explain why they say "You're welcome" instead of "Thank you." However, this does not match what Jeneta observes. She notes that customers say "Thank you" to salespeople, not "You're welcome." Also it doesn't explain the different behaviour when it comes to friends.
Rule out A. B) Salespeople are often instructed by their employers to thank customers, whereas customers are free to say what they want.While this may be true, it doesn't explain why customers respond with "Thank you" instead of "You're welcome."
Eliminate B. C) Salespeople do not regard customers who buy from them as doing them a favor.This focuses on the salesperson’s perspective, but it doesn't address why customers respond with "Thank you."
Eliminate C. D) The way that people respond to being thanked is generally determined by habit rather than by conscious decision.This suggests that people respond automatically, but it doesn't explain the specific discrepancy between responses in commercial transactions versus personal favors. We don't know which one is a habit and which is a conscious decision when comparing behaviour of customers and friends.
D is out.E) In a commercial transaction, as opposed to a favor, the customer feels that the benefits are mutual.This is the best explanation. In a commercial transaction, both the customer and the salesperson benefit: the customer gets a product, and the salesperson makes a sale. Since the benefits are mutual, the customer may feel that it's appropriate to say "Thank you" as well, whereas in a favor, the recipient feels like they're the sole beneficiary and responds with "You're welcome."
The correct answer is
E) In a commercial transaction, as opposed to a favor, the customer feels that the benefits are mutual. This explains why customers say "Thank you" instead of "You're welcome" in commercial transactions.