To be in the third normal form, a. each non-key column must depend only on the primary key b. each non-key column must not depend on the primary key c. each non-key column must contain repeating values d. all of the above

Answer: each non key column must depend only on the primary key

Explanation:

To be in the third normal form, each non-key column must depend only on the primary key that is, it must be splitted into smaller forms and first identify the smaller objects to see what separates them, The primary key is a column, or set of columns, that allows each row in the table to be uniquely identified, no two rows in a table with a primary key can have the same primary key value.

each non-key column must depend only on the primary key