In the relational model, database schema has lossless join property if the join produces the same structure as the original relation ? no further decomposition is possible the intersection of the relations is empty the join produces the same tuples as the original relation If set S (A, B,C) is a candidate key for the relation R(A, B, C, D, E), then which of the following must be true ? (A, B,D) must also be a candidate key for R D A, B or A,C or B, C must also be a candidate key for R D A, B, C, D must also be a candidate key for R none of these All of thel following are reasons for leaving a schema in a lower normal form except Desire to keep related items together in the same relation Performance requirements Desire to preserve functional dependencies in the same relation Desire to reduce replication