Identify incorrect statement about primary keys

In a relational database, which of the following claims about primary keys is not correct? Options:

• A. Any column included in the primary key must disallow NULL values.
• B. Any column included in the primary key must contain distinct values.
• C. A table may define no more than one primary key.
• D. A primary key can be declared at the table level or at the column level. Overview: This item tests understanding of primary keys and the schema constraints associated with them in relational databases, covering data integrity, uniqueness, NULL handling, composite keys, and where constraints can be declared, within the Software Engineering Fundamentals domain.