The boss stressed the criterion that a qualified waiter must do every service ______ the satisfaction of his customers.

A．has made all people see the danger of drugs
B．has succeeded in dissuading people from using drugs
C．has been effective only to a certain degree
D．has proved to be a total failure

A．effectively deterred marijuana use
B．was rejected by young marijuana users
C．did not picture the danger of marijuana realistically
D．was welcomed by marijuana users because it told them how to get high