Data scientists surveyed 100 coffee and tea drinkers over a 1-month period to determine a connection between caffeine consumption and sleep disorders. Respondents were asked questions regarding the amount of coffee or tea consumed daily, dietary habits, sleep habits, and exercise levels. Based on this survey, the data scientists claim that people who drink tea exclusively have moreincidents of insomnia than people who drank coffee exclusively.

Before publishing their findings, the data scientists have asked you to review their claim. In the space below, indicate possible threats to validity faced by this study.

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