To change "Hansen" into "Nilsen" in the "LastName" column in the "Persons" table, you would use the UPDATE statement. Let's go through each option to understand why it is correct or incorrect:
Option A) MODIFY Persons SET LastName='Nilsen' WHERE LastName='Hansen' - This option is incorrect because the correct keyword to use for updating records in SQL is UPDATE, not MODIFY.
Option B) MODIFY Persons SET LastName='Hansen' INTO LastName='Nilsen' - This option is incorrect because the INTO keyword is not used in the UPDATE statement. The correct syntax is UPDATE table_name SET column_name = new_value WHERE condition.
Option C) UPDATE Persons SET LastName='Hansen' INTO LastName='Nilsen' - This option is incorrect because, again, the INTO keyword is not used in the UPDATE statement. Additionally, the new value should be 'Nilsen', not 'Hansen'.
Option D) UPDATE Persons SET LastName='Nilsen' WHERE LastName='Hansen' - This option is correct. The UPDATE statement is used to modify records in a table. In this case, it will update the "LastName" column in the "Persons" table, setting the value to 'Nilsen' for all records where the current value in the "LastName" column is 'Hansen'.
Therefore, the correct answer is D.