The CFO of a consulting engineering firm is deciding between purchasing Ford Explorers and Toyota 4Runners for company principals. The purchase price for the Ford Explorer will be $30,500. Annual maintenance costs for the Explorer are expected to be $675 per year more than that of the 4Runner. The purchase price for Toyota 4Runners is 37,750 The trade-in values after 3 years are estimated to be 50% of the first cost for the Explorer and 60% for the 4Runner. (a) what is the incremental ROR between the two vehicles? (b) Provided the firm's MARR is 18% per year, which vehicle should it buy? a) The incremental ROR between the two vehicles is 1%. b) The firm should buy (Click to select)as the incremental ROR is (Click to select) the MARR