AcademicGround >> psychology question

dr. jones conducts a research study the effects of a new drug that is intended to reduce the craving for alcohol. a group of alcoholics who are being treated at a clinic is selected for the study. one-half are give the drug along with their regular treatment, and the other half recieves a placebo. the doc records whether or not each individual is still sober after 6 months. a) what is the independent variable? b) identify the number of levels of the independent variable. c) what is the dependent variable? d) if the participant in the drug group are older on average than the individuals in the placebo group, then participant age is a __________ variable. i think i know most of the answers would just like some help from some advanced students. thanks if you will help.