Gabriel operates a tree-trimming business in maine. he charges the perfectly competitive price of $47 per hour. the marginal cost of working the 36th hour each week is $42; the marginal cost of working the 37th hour is $44; the 38th hour is $46; and the 39th hour is $48. how many hours should he work each week? a)he should work 40 hours per week, because he can always earn more revenue by working more. b)he should work 39 hours per week, because he would have to lower his price if her wanted to work more than that. c)he should work 38 hours per week, because this is the workload that maximizes his net gain. d)he should work 36 hours per week, because the marginal cost of working rises after this point