A experiment is a study designed so that neither the subjects nor the

experimenters know which subjects are in the treatment group and which

ones are in the control group.

O

A. placebo-effect

O

B. control

O

C. double-blind

O

D. biased

C. double-blind

Step-by-step explanation:

A double-blind study is a study where neither participants nor experimenters know which subjects are receiving the treatment.

This method is really useful to minimize possible biased conclusions about the experiment.

Therefore, the right answer is C, the situation described refers to a double-blind study.