The statement which has not been mentioned in the passage is______A．business, cards are a

The statement which has not been mentioned in the passage is______

A．business, cards are a vulgarization of the nineteenth—century social calling card

B．The calling card system was especially cherished by these who made no distinction between manners and mere form

C．most people thought it improper to use business cards for social purposes

D．everyone makes his living by selling something