please answer the three questions ASAP

Practice Question 18 Sales mix is: a measure of the relative percentage in which a company's products are sold important to sales managers but not to accountants. easier to analyze on absorption costing income statements. O a measure of the relative percentage of a company's variable costs to its fixed costs. Practice Question 19 Net income will be: equal as long as total sales remain equal, regardless of which products are sold. greater if more lower-contribution margin units are sold than higher-contribution margin units. unaffected by changes in the mix of products sold. greater if more higher-contribution margin units are sold than lower-contribution margin units. Practice Question 20 In general, a company should sell more units of products with a higher contribution margin. a lower contribution margin. a higher selling price. None of the above is correct