Examine the data from the EMP table: The COMMISSION column shows the monthly commission earned by the employee.Which three tasks would require subqueries or joins in order to perform in a single step?（）

• A、Deleting the records of employees who do not earn commission.
• B、Increasing the commission of employee 3 by the average commission earned in department 20.
• C、Finding the number of employees who do NOT earn commission and are working for department 20.
• D、Inserting into the table a new employee 10 who works for department 20 and earns a commission that is equal to the commission earned by employee 3.
• E、Creating a table called COMMISSION that has the same structure and data as the columns EMP_ID and COMMISSIONS of the EMP table.
• F、Decreasing the commission by 150 for the employees who are working in department 30 and earning a commission of more then 800.