Please help with explanation ASAP. Thanks

1.Virus Stopper Inc., a supplier of computer safeguard systems, uses a cost of capital of 10 percent to evaluate average-risk projects, and it adds or subtracts 2 percentage points to evaluate projects of more or less risk. Currently, two mutually exclusive projects are under consideration. Both have a cost of $ 352 and will last 4 years. Project A, a riskier-than-average project, will produce annual end of year cash flows of $ 105 . Project B, of less than average risk, will produce cash flows of $ 233 at the end of Years 3 and 4 only.