2.14. A study is planned about whether passive smoking (being exposed to secondhand cigarette smoke on a regular basis) leads to higher rates of lung cancer.

(a) One possible study would take a sample of children, randomly select half of them for placement in an environment where they are passive smokers, place the other half in an environment where they are not exposed to smoke, and then 60 years later observe whether each person has developed lung cancer. Would this study be experimental, or observational? Why?

(b) For many reasons, including time and ethics, it is not possible to conduct the study in (a). Describe a way that is possible, and indicate whether it would be an experimental, or observational, study.