The number of attributes in a relation is called the ________ of the relation.

Correct option is A

The number of attributes in a relation is called the degree of the relation. In the context of relational databases, a relation is essentially a table, and the attributes (or columns) of the table are counted to determine the degree.
Important Key Points:
1. Degree of a Relation: The degree of a relation refers to the number of attributes (columns) it has.
2. Relation Structure: A relation consists of rows (tuples) and columns (attributes), and the degree counts the number of columns.
3. Cardinality vs Degree: While the degree refers to the number of attributes, cardinality refers to the number of tuples (rows) in the relation.
Knowledge Booster:
· Option (b): Domain refers to the set of possible values that an attribute can take. It is not related to the number of attributes in a relation.
· Option (c): Cardinality refers to the number of tuples (rows) in a relation, not the number of attributes.
· Option (d): Tuples refer to the rows of a relation, not the number of attributes.