The correct option is D. The CHECK constraint in the view ensures that all rows in the view satisfy the condition specified in the WHERE clause, i.e., department_id must be 80. An UPDATE statement that tries to change department_id to a value other than 80 will violate this CHECK constraint. Therefore, the statement 'UPDATE emp80 SET department_id = 90 WHERE department_id = 80;' will violate the CHECK constraint, as it attempts to change department_id to 90.