With respect to relational databases, which of the following statement$($s$)$ is $($are$)$ true?

The referential integrity rule ensures that there are no update anomaly problems with the foreign keys.

A delete anomaly occurs when deleting a row has unintended consequences.

Each relational table row is called a couple and contains data about a specific item in the table; each column contains data about an attribute of that item.

The normalization process is used to create a set of relational tables in $3$NF$.$

In a relational database, there can be no more than two values per cell.