25Which of the following is TRUE about portfolio duration?

Group of answer choices

A. It should be used only to calculate price changes for small changes in yield.

B. It is useful only when we think about a parallel (i.e. yields for all maturities increase or decrease by the same amount) shift in yield curve.

C. It is NOT useful when we have a NON-paralled shift in the yield curve.

D. All of the above.