In a recent study to establish the effectiveness of a new cancer drug, subjects were divided into three groups. Group A got a known and effective cancer drug, group B got the new experimental compound, and group C got a combination of the two drugs. In this study the nurses administering the drugs did not know which group or what drug was being administered to their patients. Which of the following is a correct statement about this study?

A. It was a blind study because subjects did not know the treatment they were receiving.

B. It was a double-blind study because neither the subject nor the experimenter knew what the treatment for a patient was.

C. It was not a blind study because there was no placebo.

D. It was not a blind study because patients knew they were participating in a study.