1. Defined below are three relations' schemas and their sets of functional dependencies. R₁(A, B, C, D) A → BCD C → AB R₂(E, F, G, H, I, J, K) E

→ FG EFG H R₁(L, M, N, O, P, R) L MN LN → OPR R → LM a) For each of the relations R₁, R₂, and R3, check which of the following are candidate keys (can be more than one for each relation, or none). R₁: A, B, C, D, AB, BC, ABC R₂: E, FG, EFG, EIJK R₁: L, N, R, LN, MR, NMR b) For each of the relations R₁, R₂, and R, determine if it is in 3NF. c) For each of the relations R₁, R2, and R3 determine if it is in BCNF.