Atypical customer who buys from a firm has a demand given by p = 90 - 3 q. the firm has a constant marginal cost mc = $18 and no fixed cost. it currently uses a uniform pricing strategy (i. e., it charges a single price for all the units it sells), but it is contemplating to switch to the following block pricing strategy: "buy the first 5 units at a price of $75 per unit, and any subsequent unit at a price of $54 per unit." compared with uniform pricing, profits per customer under the above block pricing are

(a) the same as in uniform pricing
(b) $450 greater under block pricing
(c) $105 greater under block pricing
(d) lower than under uniform pricing