Which one of the following is true? I. A premium bond has a coupon rate below market interest rate. II. As time passes, price of zero-coupon bond rises and approaches par value until maturity date. III. Market interest rate is positively associated with bond price IV. The longer the maturity of the bond, the greater the sensitivity of its price to fluctuations in the interest rate. A. I&II only B. II&IVonly C. I&IV only D. Ionly