Which of the following statement is NOT correct for the keys in relational databases?

Question $4$ options:

A super key is a set of one or more attributes that, taken collectively, allow us to identify uniquely a tuple in the relation.

We are often interested in super keys for which no proper subset is a super key. Such minimal super keys are called candidate keys.

Primary key denotes a candidate key that is chosen as the principal means of identifying tuples within a relation.

A key $($whether primary, candidate, or super$)$ is a property of the individual tuples, rather than of the entire relation.