Shoppers are also less likely to queue for long if the item they are buying is of low value, and ____ food and drink shopkeepers are having to find new ways to deliver good customer service.

A．in the end

B．after all

C．as a result

D．on the contrary

甲乙在买卖合同中约定：甲先付款，乙再发货。后甲未付款却要求乙发货，乙予以拒绝。根据合同法律制度的规定，乙享有的抗辩权是（）。

A.同时履行抗辩权

B.先履行抗辩权

C.不安抗辩权

D.先诉抗辩权