Explanation please

Hi @Anna, thanks for your post. This is a Paradox question. The stimulus presents us with some facts, which in turn establish a discrepancy or paradox of some sort. The question stem asks you to identify information that would help to explain or resolve the discrepancy/paradox. Answer choice (E) does this. Jeneta is comparing a commercial transaction ("when a salesperson thanks a customer for making a purchase") with what happens when a friend does a friend a favor. Answer choice (E) explains why, perhaps, a commercial transaction is different from a favor, which in turn may explain why people reply to a salesperson with "thank you" and to a friend with "you're welcome." Answer choice (D) does not explain the discrepancy. Even if people respond to a "thank you" in a habitual way, this does not tell us HOW they habitually respond. Is it with a "thank you" or with a "you're welcome"? Moreover, notice how this answer choice does not help us understand why people are responding to salespeople with a "thank you" rather than with a "you're welcome." That is really what Jeneta is trying to understand, right? Hope this helps! Please let us know if you have any additional questions.