A recent computer market survey shows that, based on the percentage of student purchasers of a brand among all purchasers, A and B computers rank in the top two, with 68% and 52% respectively. However, in the past 6 months Of the students buying computers, the domestic C brand has always ranked first. Which of the following is true is most helpful in explaining the above contradiction. ['The establishment of rankings by relevant institutions affects the consumer choice of students to a certain extent.', 'The ratio of B. C student buyers to their buyers has also been higher than other brands for a long time.', 'Compared with A and B brands, C brand computers are more cost-effective and more in line with student requirements.', 'The percentage of student purchasers of a certain brand to the total number of student purchasers of each brand is different from the percentage of student purchasers of a certain brand to the total purchasers of the brand.']