Assume a project has normal cash flows (i.e., the initial cash flow is negative, and all other cash flows are positive). Which of the following statements is most correct?

1. All else equal, a project's IRR increases as the cost of capital declines.
2. All else equal, a project's NPV increases as the cost of capital declines.
3. All else equal, a project's payback period increases as the cost of capital declines.
4. Answers a and b are correct.
5. Answers b and c are correct.