A question in New Prep. Can someone help me figure it out???

srosalita

119.(28734-!-item-!-188;#058&003375)(GWD 17-Q30)



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?

A. 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.

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 rateat which people tip food servers in Pennsylvania does not vary with how expensive a restaurant is.

E. 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.


The correct answer is B, however I choose D. Both answers mention that one factor doesn't not change, but why B is correct instead of D? The tip rate also can influenced by restaurant level, if it is a constant rate, then we can tell that the increasing tip rate is contributed to "thank You".

B, regularly seeing is it means that we see it frequently, or we just see it normaly? If regularly seeing " thank you" can't change earlier habits, then the increasing tip shouldn't be contributed to "thank You".

CAN SOME NN CAN HELP ME??????

九段泡面高手

LZ made an incorrect assumption that "regularly seeing thank you can't change earlier habits" .      

Notice the words that B uses: patrons will not revert to earlier habits!!

That means: shown "thank you", patrons have changed their habits, they will pay more tips.     B argues: even though patrons see "thank u" all the time, they will never get used to it and will never be able to ignore it, they will not revert to earlier habits that they pay less tips, they will still pay more 3% tips