Which of the following best describes a composite key?

A.
A composite key is a primary key that consists of the first two attributes of a relation.

B.
A composite key is a primary or foreign key defined by its parent keys.

C.
A composite key is a foreign key that consists of the same attributes as the primary key from a related table.

D.
A composite key is a primary or foreign key that consists of two or more attributes of a relation.