Which of the following most logically completes the argument?
According to experts on shopping behavior, more shoppers would shop at Jerrod’s department store if they were offered the convenience of shopping carts.In fact, even if the amount spent by these additional customers only just covered the cost of providing the carts, providing carts would still probably increase Jerrod’s profits, since _______.
A. the layout of Jerrod’s is open enough to accommodate shopping carts comfortably
B. several department stores that compete with Jerrod’s have begun to make shopping carts available to their customers
C. there are some potential customers who would not be enticed to shop at Jerrod’s by the availability of shopping carts
D. stores that make shopping carts available to customers usually have to hire people to retrieve them from parking areas
E. a customer with a shopping cart buys more, on average, than a customer without a cart
我可以按照排除选出答案是E，但是原文中那句the amount spent by these additional customers only just covered the cost of providing the carts是什么意思啊？不是说新顾客购物亮与提供车的价钱持平么，那E不就矛盾了么！！！ 脑子不够用啊！！！求NN解答哇！！
OA E：有购物车的话，消费者会买得更多。这不就弥补了GAP嘛~虽然新增的顾客刚刚抵消购物车的cost，但是revenue会增加，profit就会increase作者: 夏天的雨默 时间: 2013-7-15 10:43
我想是不是因为虽然
the amount spent by these additional customers only just covered the cost of providing the carts 额外的顾客带来的收入只能覆盖成本
但是 a customer with a shopping cart buys more, on average, than a customer without a cart 其他的顾客会因此而购买更多，因此会带来利润。
我选的是B，但是错了，后来想原文要求能够提高利润，而B 和提高利润无关。
不知道想法对不对，求大牛指点！