What type of group consists of subjects who do not receive the active treatment in an experiment?

The correct answer is the control group. In experimental research, the control group serves as a baseline for comparison against the experimental group, which receives the active treatment or intervention. Participants in the control group are not exposed to the treatment under investigation, allowing researchers to determine the effect of the treatment by comparing outcomes between the two groups. This design helps to control for external variables that might influence the results, ensuring that any observed effects can be attributed to the treatment itself rather than other factors. The control group plays a crucial role in validating the experiment by providing data that helps to assess the effectiveness of the intervention.