You have been asked to help maintain a database where you work. The DBA has approached you with a report that shows some mismatches. For instance in the PRODUCT table, the ProductID $2014$ shows up in ORDER$\_$ITEM but does not show up in PRODUCT. The DBA has fixed this particular error but wants a more permanent solution. What would be your suggestion?

To add a foreign key constraint on the ProductID column in PRODUCT.

To add a unique constraint on the ProductID column in ORDER$\_$ITEM.

To add a primary key constraint on the ProductD column in ORDER$\_$ITEM.

To add a foreign key constraint on the ProductID column in ORDER$\_$ITEM.