In an experiment, one group of participants is exposed to treatment, another is exposed to an application identified to them as treatment, and another is not exposed to any treatment. in such a procedure, the participants who are not exposed to any form of treatment, either genuine or false, are classified as the group.

Control group

Explanation:

In an experiment in which we are trying to find whether a treatment is actually effective or not one group is not exposed to the actual treatment while another group receives the actual treatment.

This is done in order to remove the influence of confounding variables in the experiment. A confounding variable is a variable that looks like it influences the dependent variable and the independent variable.

It needs to be made sure that the effect of the treatment which is observed is caused by only the treatment and nothing else. If the results of the study show that the treatment group only produces the desired results and the control group does not show any effects then the treatment has been successful.

it should be d or b but i'm sure it's d

c is the newer have a great day