Please briefly discuss the following four questions: (a) (6%) Briefly discuss the different between the internal rate of return (IRR) and the expected rate of return (r) of a project? Explain why if the IRR is greater than the expected rate of return (r), the NPV of the project is positive. (b) (6%) Suppose that the expected return (r) of stock A is lower than stock B but its standard deviation (s or risk) is higher than those of stock B. Stock A, with lower return and higher risk, is considered to be inferior than stock B. Would a rational investor include stock A (an inferior asset) into his/her investment portfolio? Briefly discuss. (c) (6%) Discuss why we use the after-tax rdebt (cost of debt) instead of the before-tax rdebt to compute the WACC. (d) (7%) Suppose that the management of a firm reject a negative NPV project. The rejection reason he/she gives to his/her colleagues is that the project is losing money. Briefly comment on his/her rejection reason