Net Income Planning Nolden Company has charged a selling price of $24 per unit, incurred variable costs of $15 per unit, and total fixed costs of $108,000. What unit sales volume is necessary to earn the following related amounts of net income before income tax? a. $18,000; b. $27,000; or c. equal to 20% of sales revenue. Round UP answers to the nearest unit, when applicable. (a) Answer units (b) Answer units (c) Answer units