What should be the upper limit of the solution to match h(n) perfectly to the desired response hd(n)?

What should be the upper limit of the solution to match h(n) perfectly

1.	What should be the upper limit of the solution to match h(n) perfectly to the desired response h_d(n)?
A.	L
B.	L+1
C.	L-1
D.	L+2
Answer» D. L+2