Rusty Co. sells two products, X and Y. Last year, Rusty sold 5,000 units of X and 35,000 units of Y. Related data are: Unit Selling Unit Variable Unit Contribution Product Price Cost Margin X $110.00 $70.00 $40.00 Y 70.00 50.00 20.00 What was Rusty Co.'s sales mix last year? a. 58% X, 42% Y b. 12.5% X, 87.5% Y c. 60% X, 40% Y d. 30% X, 70% Y