Which of the following statements regarding convertible is correct?

a. The coupon interest rate on a firm's convertibles is generally set higher than the market yield on its otherwise similar straight debt.

b. For equilibrium to exit, the expected return on a convertible bond must normally be between the expected return on the firm's otherwise similar straight debt and the expected return on its common stock.

c. Investors are willing to accept a lower rate on a convertible than on otherwise similar straight debt because convertible are less risky than straight debt.

d. One advantage of convertibles over warrants is that the issuer receives additional cash money when convertibles are converted.

e. None of the above.