Explanation: A Table is in 4NF if and only if, for every one of its non-trivial multivalued dependencies X \twoheadrightarrow Y, X is a superkey—that is, X is either a candidate key or a superset thereof. 6. If a multivalued dependency holds and is not implied by the corresponding functional dependency, it usually arises from one of the following sources.
A. A many-to-many relationship set
B. A multivalued attribute of an entity set
C. A one-to-many relationship set
D. Both a and b
Answer:A
Explanation: A Table is in 4NF if and only if, for every one of its non-trivial multivalued dependencies X \twoheadrightarrow Y, X is a superkey—that is, X is either a candidate key or a superset thereof. 6. If a multivalued dependency holds and is not implied by the corresponding functional dependency, it usually arises from one of the following sources.
A. A many-to-many relationship set B. A multivalued attribute of an entity set C. A one-to-many relationship set D. Both a and b