Problem 2. [15 points] Suppose we have the following three tuples in a legal instance of a relation S with four attributes ABCD: t1 = (1,7,9,1), t2 = (4,2,3,4), and t3 = (5,7,9,1).

1. Which of the following dependencies do not hold over the relational schema S and which one that could potentially hold?

(a) A B (b) B C (c) B A (d) BC A (e) BC D 2. Can you identify any functional dependencies that do hold over S? (think carefully for this!)