In an experiment comparing a treatment group to a water-injected group, the group receiving water serves as

• A. A control group
• B. An experimental group
• C. A test group
• D. An exercise group

Answer: (A)

The main idea is using a baseline to see what the treatment actually changes. The water-injected group serves as a control because it undergoes the same procedure as the treatment group but doesn’t receive the active intervention. This creates a neutral comparison point, so any differences observed can be attributed to the treatment itself rather than to the injection process, handling, or other variables. The group that gets the treatment is the experimental condition, not the control. So the water-injected group is the control group, used to gauge the true effect of the treatment.