Suppose we want to compute (R(a, b) S(a, c)) T(a, d) in the order indicated. We have M = 101 main-memory buffers, and B(R) = B(S) = 2000. Because the join attribute a is the same for both joins, we decide to implement the first join R S by a two-pass sort-join, and we shall use the appropriate number of passes for the second join, first dividing T into some number of sublists sorted on a, and merging them with the sorted and pipelined stream of tuples from the join R S. For the values of B(T) should we choose for the join of T with R S: A. A one-pass join: i.e.. we read T into memory, and compare its niples with the tuples of R S as they are generated. B. A two-pass join; i.e.. we create sorted sublists for T and keep one buffer in memory for each sorted sublist. while we generate tuples of R S