4. The Classic Pen Company manufactures and sells pens. Currently, 90,000 units are sold per year at $1.75 per unit. Fixed costs are $68,000 per year. Variable costs are $0.58 per unit. The tax rate is 21% a. What is the current annual operating income? b. What is the current breakeven point in revenue (\$)? c. Compute the new operating income for each of the following changes and compare to the baseline you calculated in part (a) above. You can use the table below to organize your answer. I. A $0.04 per unit increase in variable costs. All other costs remain the same as in part (a). II. A 10% increase in fixed costs and a 10% increase in units sold. All other costs remain the same as in part (a), including the initial variable costs of