9. The bank manager points out that Gru has failed to turn a profit on his evil schemes, and as such has been unable to pay back many of his loans. If that is the case, we know that... a. The total revenue generated by Gru's schemes is greater than the total cost of his operations. b. The marginal revenue generated by his theft of the Times Square Jumbotron exceeded the marginal cost of pulling off the heist. c. The total cost of Gru's schemes is greater than the total revenue generated by those exploits. d. There are no costs - variable or fixed - incurred by Gru in the production of his evil schemes