3 pts Question 18 Which of the following would decrease unit contribution margin the most? (Hint: assume amounts, then simulate each condition/option independently. 1. 15% decrease in selling price 2. 15% increase in selling price 3. 15% decrease in variable costs and expenses 4. 15% increase in variable costs and expenses O1 02 3 04 3 pts Question 17 Once the break-even point has been reached, operating income will increase by the 1. Gross margin per unit for each additional unit sold 2. Contribution margin per unit for each additional unit sold 3. Fixed unit per unit for each additional unit sold 4. Variable cost per unit for each additional unit sold O1 O2 03 04