Coronado Industries sells two types of computer hard drives. The sales mix is 30% (Q-Drive) and 70% (Q-Drive Plus) based upon quantity of units sold. Q-Drive has a unit variable cost of $ 100 and a selling price of $ 170.Q-Drive Plus has a unit variable cost of $ 120 and a selling price of $ 180. The weighted-average unit contribution margin for Coronado is O $63. O $85. O $67. O $ 170