When deciding whether to add or delete a department, managers should keep the department as long as $\_\_\_\_\_\_\_\_$ from the department exceeds $\_\_\_\_\_\_\_\_.$

Question $21$ options:

$1)$

contribution margin; variable costs

$2)$

contribution margin; common costs

$3)$

contribution margin; avoidable fixed costs

$4)$

contribution margin; unavoidable fixed costs