Add 2d array in a 3d array

I have a matrix A = rand(10,5,10) and a matrix B = rand(10,10) and i would like to concatenate then along the second axis into a matrix C of shape (10,6,10)

[Sindar]

try:

C = A;
C(:,6,:) = B;

[Alan De maman]

Thank you Sindar, it worked as expected.