When performing sales mix analysis, which one of the following is true: O a. Producing and selling more units of the product with a higher contribution margin would likely decrease the breakeven point O b. The sales mix is usually assumed to change, Oc. Shifting the sales mix to the product with a lower contribution margin will likely increase the overall contribution margin O d. Making changes to the sales mix will likely cause no change in the breakeven point Oe. Normally the calculation of the breakeven point for multiproduct is much simpler than that for a single product