how to find matrix in a matrix?

i have matrix a and b. matrix b is created from matrix a components(rows in this case). now i want to find out from which row of matrix a did matrix b created?

for example:

a=[4 5 7;5 8 9;6 3 1;9 8 5;7 6 5]

b=[4 5 7;6 3 1;9 8 5]

answer:

1;3;4

Answer 1

[Matt J]

Use the command ismember(...,'rows')