In a medical study, a group of patients are identified who are free of a particular disease. The researchers collect data on their alcohol consumption. These individuals are then followed over some specified time period to determine whether they get this disease or not. The relationship between the probability of getting the disease during this time period and alcohol consumption is then analyzed. Which of the following statements is true?
1) This is best described as an observational study.
2) The explanatory variable is whether or not the patients get disease.
3) The response variable is whether or not the patients get disease.
4) This study is best described as an experiment.
5) The explanatory variable is the patients' alcohol consumption.
6) The response variable is the patients' alcohol consumption.