please explain. thanks

Here are the cash flows for two mutually exclusive projects: Project/Year 1 2 3 A -$20,000 $8,000 $8,000 $8,000 B -$20,000 0 0 $25,000 Which project should be selected based on a) payback period b) net present value (using a 5% discount rate) c) internal rate of return d) profitability index e) accounting rate of return