A Superkey is:Select one:a.Every superkey is a primary keyb.A superkey is an attribute or a set of attributes that can uniquely identify a tuplec.A superkey is a tuple or a set of tuples that can uniquely identify an attributed.Every superkey is a candidate key

A Superkey is:

What is a candidate key?Group of answer choicesA super key with no redundant attributes.A key that can have duplicate values.A key that is always used as a primary key.A key that contains a composite of two or more foreign keys.

Consider attributes ID, CITY and NAME. Which one of this can be considered as a super key?Question 2Answera.CITY, IDb.NAMEc.CITYd.ID

If a proper subset of X is a superkey, then X cannot be a key.Question 4Select one:TrueFalse

______________ is the superset of all keys in a relation.