You sent out five RFPs (requests for proposal) to compare cost and benefits of a new patient check-in kiosk. You only received two of the RFPs back. Vendor A give you a cost of $13,800. The cost savings per month for this first proposal is projected at $375. The second proposal from Vendor B is at a cost of $7,100, but the software is not as sophisticated. Vendor B's kiosk would have a cost savings per month of $150. Which payback period is quicker?