A corporate bond is currently trading at a price that is above its par value. Which of the following statements is the BEST explanation of why this is happening? O A. The bond's coupon rate is higher than its yield to maturity (YTM). O B. Interest rates must have increased since the bond was issued. O C. This bond has become relatively more risky. O D. The yield to maturity (YTM) is equal to investors' average required return on this bond