The decision rule for constrained optimization is to select the level for each activity at which a. marginal benefit equals marginal cost for each...

The decision rule for constrained optimization is to select the level for each activity at which a. marginal benefit equals marginal cost for each activity. b. total benefit equals total cost for each activity. c. marginal benefit per dollar of marginal cost is equal across all activities. d. total benefit per dollar of total cost is equal across all activities.