Which of the following statements is correct regarding the effects of interest rate shift on fixed-income portfolios with similar durations?
A. A barbell portfolio has greater convexity than a bullet portfolio because convexity increases linearly with maturity.
B. A barbell portfolio has greater convexity than a bullet portfolio because convexity increases with the square of maturity.
C. A barbell portfolio has lower convexity than a bullet portfolio because convexity increases linearly with maturity.
D. A barbell portfolio has lower convexity than a bullet portfolio because convexity increases with the square of maturity.