Bond Duration and Bond Maturity are different. Macaulay Duration is a widely used measure of a bond's sensitivity to changes in bond yields, the equation for which is: $\%$ in Bond Price $=-$Duration $*$YTM$(1+$YTM$/2).$ Which, if any, of the following may be a logical explanation why the distinction between bond maturity and duration may be important:

a$.$ Bonds have a legally contractual maturity date. However, most bonds are not held to maturity, but are sold $($liquidated$)$ at an earlier date, which changes the underlying assumptions of YTM calculations.

b$.$ A well$-$managed bond portfolio will rebalance the bonds before maturity to optimize the timing of meeting long term $($example$)$ pension payment needs.

c$.$ Given $"$a$"$ and $"$b$"$ above, the Duration becomes the practical and effective maturity of the bond for the investor, so dynamics such as "yield to duration" are more realistic than "yield to maturity."

d$.$ All of the above.

e$.$ None of the above.