Which of the following is not a problem faced by investors trying to manage a fixed income portfolio against an index?

Select one:

a. Capitalisation weighting the portfolio can result in over-exposure to highly leveraged firms.

b. Bonds are generally more illiquid than other asset classes such as equities.

c. Bond indices that appear similar can have significantly different risk and performance due to the heterogeneity of bonds.

d. Bond prices never change given their coupon payments are fixed.

e. Index composition changes frequently resulting in high transaction costs.