The correct answer to the question is:
(i) Primary Key
Explanation:
1. A field that has a unique value for every record in a database table is called a Primary Key.
2. The primary key ensures that each record in the table is uniquely identified.
3. It cannot have null or blank values because it must be unique for each record to serve its purpose effectively.
4. This uniqueness is crucial for maintaining data integrity and facilitating efficient data retrieval operations in databases.
In summary, a Primary Key is a unique identifier for each record in a database table and cannot be left blank to maintain its uniqueness and integrity.
