Determine whether the study depicts an observational study or an experimentA poll is conducted by a school's math department in which forth - grade students are asked if they prefer to be in their math class or science classchoose the correct description of studya. the study is am experimental because the study examines indiveduals in a sample ,but does not try to influence the variableb. the study is an observational study because the study examines individuals in a samplec. the study is an experiment because the researchers control one variable to determine the effect on the respondsd. the study is observational study because the researcher scontrol one variable to determine the effect on the response variable