For price discrimination to work ________. A: the market must be segmentable and the segments must show similar intensities of demand B: members in the lower-price segment must be able to resell the product to the higher-price segment C: competitors must be able to undersell the firm in the higher-price segment D: the practice must not breed customer resentment and ill will E: the extra revenue derived from price discrimination must not exceed the cost of segmenting and policing the market