【单选题】

According to the passage, which of the following statements is true
A．The Chinese people have to pay tips in western countries.

B．The westerners don' t have to pay high tips in their own country.
C．Barbers, hotel bellboys and all sorts of other people can earn a living if they are not tipped.
D．Tipping varies from place to place, generally in the area of 20% of your bill.