You are considering two projects, Project C and Project D. Project C requires an initial investment of $8,000,000 and is expected to generate cash inflows of $2,000,000 per year for the next five years. Project D requires an initial investment of $5,000,000 and will generate $1,000,000 in the first year, $1,500,000 in the second year, $2,000,000 in the third year, $2,500,000 in the fourth year, and $3,000,000 in the fifth year. With a discount rate of 8%, calculate the NPV and IRR for each project and determine which project should be selected. Also, analyze the payback period for both projects.