Food safety has become a hot issue of concern in modern society. A social survey this year for a city showed that 29.2% of the respondents felt safe in eating, and 23.8% of the respondents did not feel safe. The survey data were 22.4% and 32.6%, respectively. Investigators asserted that the public's sense of food safety has improved this year, and the overall state of food safety is better than last year. Which of the following, if true, would most likely challenge the above findings? ['Some respondents did not express their attitudes towards food safety this year.', 'The city government has increased its management of food safety this year.', "The city's media reported multiple food safety incidents such as fake milk powder this year.", "This year's social survey has increased the number of catering operators."]