单项选择题
Imagine the offline moment in your life, suppose you go for groceries in a supermarket, buy a snack in street shops, eat at some restaurants, go to watch a movie, or take a subway, you just scan their () on their wall or at the cashier, the mobile pay pag
e would automatically pop up created by those mobile payment apps.
A.QR code
B.money
C.card
D.bill