Studies in restaurants show that the tips left by customers who pay their bill in cash tend to be larger when the bill is presented on a tray that bears a credit-card logo.現(xiàn)象：有信用卡標(biāo)志的托盤會(huì)收到更多小費(fèi)
Consumer psychologists hypothesize that simply seeing a credit-card logo makes many credit-card holders willing to spend more because it reminds them that their spending power exceeds the cash they have immediately available.
增強(qiáng)解釋可信度的選項(xiàng),
解釋是否合理的關(guān)鍵在于people who are not reminded of their own excess purchasing power paid more tips,也就是顧客是否看到標(biāo)志就被提醒到他們的信用卡
B選項(xiàng)證明了這一點(diǎn)
而A消弱了,證明很多顧客沒有被提醒到有信用卡這回事就付了更多小費(fèi)
C也是和A一樣
D也是削弱,用信用卡的人已經(jīng)意識(shí)到自己可以花超額但是付的小費(fèi)較少
E具體到某一品牌的信用卡,而題目給的解釋是顧客通過信用卡標(biāo)志意識(shí)到自己有信用卡才花更多,不能由具體的某品牌信用卡的現(xiàn)象推一個(gè)更加大,抽象的結(jié)論.