ACME INC has conducted research to estimate the profitability of its customers. Based on this research it is considering terminating about 25% of its customers, who appear to be unprofitable.

terminating a customer can only increase the firm's profit if: a. the contribution margin for the customer is negative. b. the revenue minus the fixed costs for the customer are negative. c. the fixed costs for the customer are greater than the variable costs. d. a and b are both necessary conditions. e. a, b, and c are all necessary conditions.