Assume that a perfect capital market exists. The cost of equity for all firms is 10% and the risk-free rate is 5%. All firms can borrow and lend at the risk-free rate. Which of the following statements is correct? (a) Reducing transaction costs is important. (b) Improving the firm's credit rating is important. (c) Improving operating performance is important. (d) All of the above are important goals for every firm