The correct option is A n+1Ck
First arrenging all n zero in a raw. There is only 1 way for arranging n zeros in a row. By arranging n zeros in a row, we get (n+1) positions to place once.
So number of ways arranging k once in (n+1) positions= n+1Ck
∴ Required number of binary strings of n zeros and k once that no two ones are adjacent