To enforce referential integrity, the database can return an error instead of doing the requested action or do the requested action and do the related changes to the related tables
Thus the answer is either a or b.
Explanation:
When the given data base in a table is valid and if it is consistent then it is called as referential integrity and it also refers to the consistency within the relationship. This type of database is much important because it will keep us introducing to the errors in the databases and it also checks if the reference from one table is equal to the other table.
The main function is to prevent the users from entering the wrong and inconsistent data. So in referential integrity the database will return the error instead of doing the required action or it can do the related changes to the related tables.
