Suppose relations: $R(A,B)$ and $S(B,C,D)$ (see figure). | R | | | :--- | :--- | | A | B | | 1 | 2 | | 3 | 4 | | 5 | 6 | | S | | | | :--- | :--- | :--- | | B | C | D | | 2 | 4 | 6 | | 4 | 6 | 8 | | 4 | 7 | 9 | Compute the full outer join of $R$ and $S$, where the condition is: $R.A > S.B$ AND $R.B = S.C$. Which of the following tuples of $R$ or $S$ is dangling (and therefore needs to be padded in the outer-join)?