In a study conducted in Pennsylvania, servers in various restaurants wrote "Thank you" on randomly selected bills before presenting the bills to their customers. Tips on these bills were an average of three percentage points higher than tips on bills without the message. Therefore, if servers in Pennsylvania regularly wrote "Thank you" on restaurant bills, their average income from tips would be significantly higher than it otherwise would have been.
Which of the following is an assumption on which the argument relies?
The "Thank you" messages would have the same impact on regular patrons of a restaurant as they would on occasional patrons of the same restaurant.
Regularly seeing "Thank you" written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.
The written "Thank you" reminds restaurant patrons that tips constitute a significant part of the income of many food servers.
The rate at which people tip food servers in Pennsylvania does not vary with how expensive a restaurant is.
Virtually all patrons of the Pennsylvania restaurants in the study who were given a bill with "Thank you" written on it left a larger tip than they otherwise would have.
情景：一个在宾州的研究显示，如果随机的在顾客的账单上填写Thank You，那么在那些有Thank You的账单上获得的小费比较多。因此，如果经常性的在顾客的账单上填写Thank You，那么会比之前获得更多的小费。
B选项：Correct. 经常性的看到Thank you不会改变客户的付小费习惯。如果经常性看到thank you“会”改变客户的付小费习惯，则本选项给出了随机填写Thank You和经常性填写Thank You的区别，可以削弱推理。
C选项： Thank you这个信息让餐厅客户意识到小费占据服务员很大的收入比例。
E选项：在研究中，几乎所有被出示Thank you的人都会比从前不出示Thank you时多给一部分小费。