Mithali, a financial analyst, is preparing data to engage in a data analysis project to predict revenue for the next period based on environmental considerations. She is currently reviewing the tables to validate inter$-$table rules for referential integrity. Which of the following is true about referential integrity?

The primary and foreign key fields must have the same name.

The primary key must be single$-$valued, but the foreign key can be multi$-$valuedth

All values in a foreign key should also exist as values in the corresponding primary key.

The primary and foreign key fields can have different data types.