Media A. reported that since the beginning of this year, the number of people suffering from seasonal skin diseases has risen sharply, which is caused by increasing water pollution in cities and worsening air quality. Media B. reports that the number of people with seasonal skin diseases has risen sharply. There is no relationship between urban water pollution and air quality deterioration, mainly due to people's lack of exercise and physical fitness decline. Which of the following, if true, would best challenge the views of Media B. ? ['The physical fitness of children aged 7-12 is generally lower than that of 10 years ago.', 'Most people with skin diseases in spring will get better in autumn and winter.', 'EPA acknowledges growing urban water pollution and air quality problems.', 'The number of swimmers suffering from seasonal skin diseases is increasing year by year.']