In a controlled experiment, which group experiences the test?

Question:

Scientific Method:

The scientific method uses a sequence of logical steps to investigate and answer questions concerning the natural phenomena. Scientists using the scientific method must observe the natural world, ask questions regarding their observations, hypothesize answers to their questions, design and implement experiments to test hypotheses, and analyze the results to accept or reject their hypotheses as adequate explanations of the observed phenomena or questions. In order to accurately assess hypotheses, scientists typically use controlled experiments, in which only a few specific variables are changed throughout the experiment, while other variables are held constant. This allows cause and effect relationships to be determined between specific variables.

Answer and Explanation: 1