MATLAB: All the posible combination of two matrices

Question

I have two matrix

A=[1]

and

B=[2 3 4]

find the all possible combination of these tow matrices is

the output

C=[1 2; 1 3; 1 4; 1 2 3; 1 2 4; 1 3 4; 1 2 3 4]

how to find it

Answer 1

C = [];
for j1 = 1:numel(B)
    a = nchoosek(B,j1);
    C = [C;num2cell([repmat(A,size(a,1),1),a],2)];
end