10. Which of the following statements are true? I. The convexity of a 10-year zero-coupon bond is higher than the convexity of a 10-year 6% bond. II. The convexity of a 10-year zero-coupon bond is higher than the convexity of a 6% bond with duration of 10 years. III. Convexity grows proportionately with the maturity of the bond. IV. Convexity is always positive for all types of bonds. V. Convexity is always positive for \"straight\" bonds. a. I only b. I and II only c. I and V only (1. II. III and V onlv