It is generally believed that maintaining an optimistic attitude promotes health, but a 10-year follow-up study of 70,000 women in their 50s found that subjects who have remained optimistic and pessimistic for a long time have a mortality rate and there is no difference, and researchers believe that optimism is not related to health. Which of the following, if true, would most question the researchers' conclusions? ['The pessimistic people in this study were more chronically ill, although not yet severe enough to be fatal.', 'Compared with pessimistic people, optimistic people will be more proactive in treating illness.', 'Optimistic people often do not pay special attention to the body, and sometimes some fatal diseases cannot be detected early.', 'Women are better at maintaining harmonious relationships, and good relationships help health.']