A controlled experiment is a scientific test that compares two or more groups that are kept the same except for one factor that is changed or altered. This factor is the independent variable, and its effects on the system being studied are measured. A controlled experiment uses controls, usually separating the subjects into an experimental group and a control group. The experimental group is exposed to the independent variable, while the control group is not. A controlled experiment allows researchers to determine cause and effect between variables.
According to this definition, the answer to your question is: A controlled experiment includes at least two groups, one of which does not receive the experimental treatment. This option matches the description of a control group and an experimental group in a controlled experiment.