Answer : C
In RDBMS, No Two Tuples can have All the Attribute Values same. These are some Basic Codd's Rules. Codd Proposed RDBMS model, It is called Relational Model because Every Table is a Relation (Subset of Cross Product of Attributes' Domains) in Which elements are Tuples of tables. Since RDBMS model is derived from Set Theory, No Two tuples can be Exactly same.