Question $7(5$ points$)$

The primary key of the relation added to accomplish the many$-$to$-$many relationship

must contain at least three attributes

must contain at least four attributes

is the primary key of one of the two relations involved in the many$-$to$-$many

relationship

is the combination of the primary keys of the two relations involved in the many$-$

to$-$many relationship plus possible additional attributes