Which of the following is the correct technique for representing a N:M relationship using the relational model?

Question $19$ options:

An intersection relation is created, and the key of either entity is placed as a key in both the intersection relation and in the other relation.

An intersection relation is created with a surrogate key, which is placed in each of the parent entities.

An intersection relation is created, and the keys of both parent entities are placed as a composite primary key in the intersection relation.

The key from either relation is placed as a foreign key in the other relation.