Price discrimination against old customers leads to the situation that people who know you hurt you more deeply. It is because and

A、the price set by the merchant is too reasonable;
B、a large proportion of consumers are reluctant to bear higher prices than others, even if they are willing to pay more;
C、merchants take advantage of the convenience of information technology for non-public and mandatory differentiated pricing;
D、merchants take advantage of the information asymmetry of the Internet