Which of the following statements about rero-coupon bonds is correct? Select one: a. The yields to maturity of zero coupon bonds are always lower than that of coupon bonds b. Other things being equal, a zero-coupon bond with a lower yield to maturity has a lower price c. A zero-coupon bond with a 15% yield to maturity will trade at a premium d. Other things being equal, a zero-coupon bond with a shorter maturity date has a higher price