Answer:
The correct answer is "patients with prostate cancer who received traditional treatment alone".
Explanation:
Control groups used during clinical trials must be patients that suffer from the disease at which the new treatment is prescribed for, but they are not being treated with the new drug. Given that the new drug is designed to be prescribed to treat chemotherapy in addition to traditional treatment for prostate cancer, the control group must be patients with prostate cancer who received traditional treatment alone. This control group fits the criteria of being patients with prostate cancer that are not going to receive the new treatment, but only the traditionally treatment.