Identify the statement below that is false with regards to basic requirements of a relational

database model.

A$)$ Primary keys can be null.

B$)$ Foreign keys, if not null, must have values that correspond to the value of a primary key in

another table.

C$)$ All non$-$key attributes in a table should describe a characteristic about the object identified by

the primary key.

D$)$ Every column in a row must be single$-$valued