Which is false?

a. The greater the LTV ratio, the greater the prepayment risk for mortgage-backed securities.

b. At issuance, the pool factor of mortgage-backed securities is one and decreases to zero over time.

c. Given two bonds that are similar except for their convexity, the one with greater convexity is less valuable since it provides smaller capital gains and greater capital losses for the same absolute changes in yields.

d. Bonds with a convertible provision provide lower yields than bullet bonds, if other factors are constant.