I need part b and d.

Consider the following projects: Project C5 Co -1,500 -3,000 -3,750 Cash Flows ($) c i C 2 1,500 1,500 1,500 1,500 900 0 C3 0 4,500 C4 0 1,500 1,500 1,500 1,500 a. If the opportunity cost of capital is 11%, which project(s) have a positive NPV? b. Calculate the payback period for each project. c. Which project(s) would a firm using the payback rule accept if the cutoff period is three years? d. Calculate the discounted payback period for each project