Indicate whether each of the following statements are true, false, or uncertain and explain your answer.

a. Consider two zero-coupon bonds, one with a short maturity, and one with a longer maturity. The value of the long-maturity bond is more sensitive (in % terms) to changes in interest rates than the short-maturity bond' s value.

b. If the Internal Rate of Return (IRR) of an investment project is above its cost of capital, then the NPV of the project (calculated at the cost of capital) must be positive.

c. An increase in bond yields is associated with an increase in bond prices.

d. If the yield curve is upward sloping, then the yield of a 4-year coupon-paying bond (with semi-annual coupon payments) is below the yield of a 4-year zero coupon bond.