Final answer:
The treatments in this study are the men and women who took the drug and the drug and placebo. The correct answer is option D) and E).
Step-by-step explanation:
The treatments in this study are option D) Only the men and women who took the drug and option E) The drug and placebo. In this experiment, one group of men and women in their 50's takes the drug, while the other group takes a placebo. The effects of the drug are then measured against the effects of the placebo after a period of 10 years.
By randomly assigning participants to either the drug or placebo group, the researchers are able to compare the outcomes of the two groups and determine whether the drug is effective in reducing the risk of developing arthritis. This study design allows for a controlled comparison and helps identify the specific effects of the drug. The placebo is critical for controlling the placebo effect.