Final answer:
B. Entity Integrity and Referential Integrity. Entity Integrity and Referential Integrity are the business rules that should be enforced in the database structure.
Step-by-step explanation:
The business rule(s) that should be enforced in the database structure are Entity Integrity and Referential Integrity. Entity Integrity ensures that each row in a table has a unique identifier, such as a primary key, which prevents duplicate records. Referential Integrity ensures that relationships between tables are maintained, by enforcing that foreign key values in one table must match the primary key values in another table.