What kind of key is a column or concatenated columns that are identical to the primary key of a relation in the same database?

The correct answer is a foreign key. A foreign key in a database is a column or a set of columns that establishes a link between the data in two tables. Specifically, a foreign key in one table refers to the primary key in another table. This relationship enables the database to maintain referential integrity, ensuring that relationships across tables stay consistent. When a foreign key in one table contains values that match the primary key of another table, it effectively creates a connection between the two sets of data, allowing for more complex querying and reporting.

In this context, the question specifies columns that are identical to the primary key of a relation in the same database, which aligns perfectly with the definition of a foreign key. A foreign key can be made up of one or multiple columns (concatenated columns) that match the primary key in a relational database setup, thus forming the correct answer.