Which of the following statements is CORRECT?

a). If a coupon bond is selling at par, its current yield is lower than its yield to maturity.

b) If rates fall after its issue, a zero coupon bond could trade at a price above its maturity (or par) value.

c) If rates fall rapidly, a zero coupon bonds expected appreciation could become negative.

d) If a bond is selling at a premium, this implies that its coupon rate exceeds its yield to maturity.