Adding zeros to an array

Suppose I have 2 arrays:

A=[1 2 3 4;
   2 3 4 5;
   3 4 5 6];

B=[5 1 3;
   1 3 4];

How can I append zeros to matrix B such that:

Output=[5 1 3 0;
        1 3 4 0;
        0 0 0 0];

Answer 1

[Walter Roberson]

OutPut = B;
OutPut(3,4) = 0;