1 a) Caryn is running an e-commerce on Shopii. Based on her observation, she found that 4 out of 20 types of products she listed are actually contributing 80 percent of the sales. Therefore, she decided to cut the bottom 16 types of products out from the list completely and only focus on the top 4. She also added 4 more products similar to the top 4 and the total sales doubled. Explain which principle Caryn has applied and give the advantages and disadvantages of that principle. (20 marks)