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Researchers want to know if having a TV in the bedroom is associated with childhood obesity. They administer a questionnaire to 379 twelve-year old French adolescents. After analyzing the results, the researchers determined that the body mass index of the adolescents who have a TV in their bedroom was significantly higher than that of the adolescents who did not have a TV in their bedroom.

a.) What best describes this study and why? - Is it a designed experiment study, a cross-sectional observational study, a cohort observational study, a case-control observational study or a census?

b.) What is the response variable in this study?

C.) What is the explanatory variable in this study?

d.) List a possible lurking variable in this study and EXPLAIN why it may be a lurking variable to this study?