A medical survey found that the use of lower-priced drugs for the treatment of the same type of disease is as effective as the use of higher-priced drugs at the same time. Therefore, vigorously promote lower-priced drugs to reduce medical costs. Which of the following is true that would weaken the above conclusion? (). ['the side effects of less expensive drugs are less than those of higher prices.', 'the number of times a lower-priced drug is taken per unit time and the dose to be taken each time are higher than the higher-priced drug.', 'the profit margin of lower-priced drugs is relatively small, which is not conducive to the survival of pharmaceutical companies.', 'The middle class and the rich are more inclined to use higher-priced drugs in the medical process.']