in a study, a large sample representative of the households in the us were asked about their smoking habits. the data suggested that current smokers were on average much healthier than those who recently stopped smoking. investigators concluded that smoking does not necessarily lead to worse health outcomes. consider the following statements. select the ones you agree with, based on the information given. group of answer choices this is an observational study. the results can be explained due to confounding. current smokers are different from those who recently stopped in ways that are related to health outcomes. the conclusions were justified by the data. this study is a randomized controlled experiment. in a randomized experiment, smoker and non-smoker groups are similar across all potential characteristics.