David company produced 50 defective units last month at a unit manufacturing cost of $30. The defective units were discovered before leaving the plant. David can sell them "as is" for $20 or can rework them at a cost of $15 and sell them at the regular price of $50. Which of the following is not relevant to the sell-or-rework decision? $20 selling price of defective units $30 manufacturing cost $50 regular selling price All of these are