Which of the Following Is NOT True About Referential Integrity

Multiple Choice

Which of the following is NOT true about referential integrity?

A) The matching fields on both sides of the relationship have the same data types.
B) You cannot enter a value in the foreign key field on the many side table that is not a primary key on the one side table.
C) The primary key field values on the one side of the relationship must be unique.
D) All foreign key fields and primary key fields must have values entered and cannot remain null.