Which group contains the tested variable and will give the predicted results?

• A. Experimental group
• B. Control group
• C. Positive control group
• D. Negative control group

Answer: (C)

In experiments, a positive control is used to show that the system can produce a result when the tested variable is present and expected to work. This group includes the variable and is anticipated to yield the known, predicted response, which validates that your assay or setup is capable of detecting that effect. It provides a benchmark so you can compare other groups and interpret whether observed changes are due to the variable itself. The experimental group tests the variable’s effect, but the positive control’s role is specifically to confirm that the expected outcome can occur when the variable is present.