Questions: What is the key difference between BCNF and 3NF? a.) There are no multivalued dependencies in BCNF. b. Determinants must be candidate keys in BCNF. c.) BCNF breaks down tables into as many tables as possible. d) There are no repeating groups in BCNF.

The answer is the second one (b): Determinants must be candidate keys in BCNF.

Explanation for each option: a.) There are no multivalued dependencies in BCNF.

• This statement is incorrect because BCNF does not specifically address multivalued dependencies. Multivalued dependencies are addressed in 4NF.

b.) Determinants must be candidate keys in BCNF.

• This statement is correct. The key difference between BCNF (Boyce-Codd Normal Form) and 3NF (Third Normal Form) is that in BCNF, every determinant must be a candidate key. In 3NF, a non-prime attribute can be dependent on another non-prime attribute as long as the latter is a superkey.

c.) BCNF breaks down tables into as many tables as possible.

• This statement is incorrect. BCNF does not necessarily break down tables into as many tables as possible. It focuses on ensuring that every determinant is a candidate key.

d) There are no repeating groups in BCNF.

• This statement is incorrect. The concept of repeating groups is addressed in the First Normal Form (1NF), not BCNF.

Summary: The key difference between BCNF and 3NF is that in BCNF, determinants must be candidate keys.