Sheffield Corp.sells two types of computer hard drives. The sales mix is 30% (Q-Drive) and 70% (Q-Drive Plus). Q-Drive has variable costs per unit of $150 and a selling price of $210. Q-Drive Plus has variable costs per unit of $165 and a selling price of $255. Sheffield's fixed costs are $972000. How many units of Q-Drive would be sold at the break-even point? O 12000 3600 4860 O 8400