In an experiment, 80 women with different levels of anxiety were asked to complete the same letter recognition task. At the same time, electrodes were placed on their heads to observe brain activity. The results showed that women with high levels of anxiety had more complicated EEG activities when they completed the task. It is more prone to errors. The experimenter concludes that female anxiety affects the quality of task completion. Which of the following, if true, would best refute the above conclusion? ['Women with high levels of anxiety are unfamiliar with the task before the experiment compared to other women.', 'When women are anxious, their brains are disturbed by their minds and unable to focus.', 'Female anxiety easily leads to psychological problems such as obsessive-compulsive disorder and generalized anxiety.', 'Studies have shown that anxiety and brain response error rates are positively correlated.']