Which of the following statements regarding Sinking Fund Provision is most correct? Select one: a. On balance, bonds that have a sinking fund are regarded as being riskier than those without such a provision. b. A sinking fund provision gives the issuer the right to sell bonds under specified terms prior to the normal maturity date. c. In general, sinking fund bonds are issued with lower coupon rate than otherwise similar bonds without sinking funds. d. A firm will choose to call back bonds for redemption at par value if the bonds are traded at a discount. e. A firm will choose to buy the required bonds on the open market if the bonds are treaded at a premium