17. A drug company wishes to test a new drug. A researcher assembles a group of volunteers and randomly assigns them to one of two groups---one to take the drug and one to take a placebo. In addition, the company wants the experiment to be double-blind. What is the meaning of double-blind in this situation? A) The volunteers in both groups are blindfolded when they take the drug or placebo. B) the volunteers in both groups do not know whether they are taking the drug or the placebo. C) Neither the volunteers nor the drug company executives know which volunteers are taking the drug and which are taking the placebo. D) Neither the volunteers nor the evaluator now which volunteers are taking the drug and which are taking the placebo. E) as long as the subjects are randomly assigned to the two groups, there is no need to make the experiment double-blind.