I need help with M5-14 and please explain in detail since I do not understand how consignment works.

Assessing Risk Exposure to Revenue Recognition (LO1) BannerAD Corporation manages a Website that sells products on consignment from sellers. It pays these sellers a portion of the sales price, and charges a commission. Identify two potential revenue recognition problems relating to such sales. Estimating Revenue Recognition with Right of Return (LO1) ModCloth, Inc. offers an unconditional return policy. It normally expects 2% of sales at retail selling prices to be returned before the return period expires. Assuming that ModCloth records total sales of $10 million for the current period, what amount of net sales should it record for this period? Assessing Research and Development Expenses (LO2) Abbott Laboratories reports the following (summary) income statement. Compute the percent of net sales that Abbott Laboratories spends on research and develop (R&D). Compare this level of expenditure with the percentages for other companies that are cussed in the Business Insight box on pages 5-15. How would you assess the appropriateness R&D expense level