Questions: 1 1.1.4 Quiz: Scientific Investigations Question 6 of 10 Which statement describes a controlled experiment? A. It includes only an experimental group. B. It includes only a control group. C. It includes more than one control group. D. It includes a control group and an experimental group. SUBMIT PREVIOUS

The answer is the fourth one (or D): It includes a control group and an experimental group.

Explanation for each option: A. It includes only an experimental group. - Incorrect. A controlled experiment requires both a control group and an experimental group to compare results and determine the effect of the variable being tested. B. It includes only a control group. - Incorrect. A controlled experiment must have an experimental group to test the hypothesis against the control group. C. It includes more than one control group. - Incorrect. While some experiments may have multiple control groups, the essential feature of a controlled experiment is the presence of both a control group and an experimental group. D. It includes a control group and an experimental group. - Correct. A controlled experiment involves comparing the results of an experimental group, which is exposed to the variable being tested, with a control group, which is not exposed to the variable.

Summary: A controlled experiment is characterized by the inclusion of both a control group and an experimental group to effectively test the hypothesis and observe the effects of the variable being studied.