The operating results for XYZ Ltd in 2018 are as follows: Sales 850,000 Less: Variable costs 320,000 Contribution margin 530,000 Less: Fixed costs 175,000 Net Profit 355,000 In 2019, variable costs are expected to increase by 12% while sales are expected to increase by 10%. What will be the change contribution margin ratio for XYZ Ltd from 2018 to 2019? Select one: O a. increase 0.0085 b. decrease 0.0068 c. increase 0.0068 O d. decrease 0.0085