Which of the following is NOT the standard method of distributing coupons according to the passage?
A、Package insertions
B、newspapers
C、Mails
D、door-to-door delivery
【正确答案】：D
【名师解析】:根据所提供的信息，选项D "door-to-door delivery" 不是文章中提到的标准分发优惠券的方法。其他选项A、B和C均被提及为分发优惠券的标准方式。选项A "Package insertions" 指的是将优惠券插入包裹中分发，选项B "newspapers" 指的是通过报纸分发，而选项C "Mails" 指的是通过邮件分发。因此，正确答案是D。
