Which Statement Below Is False Regarding the Basic Requirements of the Relational

Multiple Choice

Which statement below is false regarding the basic requirements of the relational data model?

A) Every column in a row must be single-valued.
B) All non-key attributes in a table should describe a characteristic about the object identified by the primary key.
C) Foreign keys, if not null, must have values that correspond to the value of a primary key in another table.
D) Primary keys can be null.