Which of the following integrity constraints ensures that no duplicate rows are present in a table?

Correct option is D

The Primary Key Constraint ensures that every row in a table is unique and identifiable. It prevents duplicate rows and enforces the uniqueness and not null properties on the specified column(s).
Example:

Important Key Points:
1. A primary key is a combination of Unique and Not Null constraints.
2. Each table can have only one primary key, but it can consist of multiple columns (composite primary key).
Knowledge Booster:
· Foreign Key: Ensures referential integrity between two tables.
· Unique Constraint: Enforces uniqueness but allows NULL values.
· Not Null Constraint: Ensures that a column cannot have NULL values.
· Check Constraint: Ensures that a column satisfies a specific condition.