Company XYZ produces and sells headphones. The company has total fixed costs of $112,000. Each headphone sells for $70 per unit and has variable costs of $50 per unit. Next year XYZ Company wishes to earn an operating income that equals 20% of fixed costs. How many units must be sold to achieve this target income level? (rounded to the nearest number) Select one: O a. 933 O b. 6,720 O c. 5,600 O d. 4,480 O e 1,120