Critical Reasoning

In a study conducted in Canada, 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 Canada 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?

(A)The "Thank you" message would have the same impact on regular patrons of a restaurant as they would on occasional patrons of the same restaurant.
(B)Regularly seeing "Thank you" written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.
(C)The written "Thank you" reminds restaurant patrons that tips constitute a significant part of the income of many food servers.
(D)The rate at which people tip food servers in Canada does not vary with how expensive a restaurant is.
(E)Virtually all patrons of the Canadian restaurants in the study who were given a bill with "Thank you" written on it left a larger tip than they otherwise would have.

OA: B

can someone explain this!!!!! can't figure out why...

Leme try:
Statement: Tips on bills marked with "Thank you" were an average of three percentage points higher than tips on bills without the message.
Conclusion:"Thank you" marked restaurant bills, would generate higher average income from tips

(B)Regularly seeing "Thank you" written on their bills would not lead restaurant patrons to revert to their earlier tipping habits.

The statement says it was a "Study" means for a limited period. Arguement assumes that restro patrons displayed more generous tipping(habit)only when they saw bills marked with Thank you.
And they would continue to display the same generous tipping habit if we regularly produce bills marked with Thank you.
What if the restro patrons revert to their habit of being less generous in tipping when they see bills marked with "Thank u" regularly. The word "regularly" is important here.

If you use what I call "the Infomercial Technique" what you would do is to set up the argument the normal way. So get the conclusion and the evidence first. The conclusion is that if servers would regularly write "thank you" on the bills that they give customers they would get larger tips. The evidence is that this was true in a limited study.

So what would be the potential problem here? What if the reason for the increased tips was that the patrons felt special to get the rare "thank you." Maybe the patrons would not feel special if this happened all the time. Choice B mentions this and then says "don't worry about it." That is the way that a correct answer to an assumption works in this article "Approaching Assumption questions like an Expert." https://www.beatthegmat.com/mba/2012/06/ ... -an-expert