Which of the following steps is necessary to create a many-to-many relationship between Entity A and Entity B?

To establish a many-to-many relationship between Entity A and Entity B, the creation of a third entity, often referred to as a junction or associative entity (in this case, Entity C), is essential. Entity C serves to hold the associations between the two entities by using reference attributes that point back to the identifiers of both Entity A and Entity B.

In this context, Entity C will have two reference attributes: one for the identifier of Entity A and another for the identifier of Entity B. This setup allows for multiple instances of Entity A to be associated with multiple instances of Entity B, facilitating the many-to-many relationship. Each record in Entity C represents a unique pairing of records from Entity A and Entity B, effectively managing the relationships between the two.

Establishing the relationship in this way avoids redundancy and ensures data integrity, making it the correct approach compared to simply adding reference attributes directly to Entity A or Entity B.