Correct Answer: B

Rationale: In an experiment, the independent variable is the one that the investigator expects to cause changes in another variable. It is the factor that is deliberately manipulated or changed by the researcher to observe its effects on the dependent variable. The purpose of manipulating the independent variable is to study its impact on the outcome, allowing researchers to establish cause-and-effect relationships in their investigations. Choice A is incorrect because the independent variable is not influenced but rather influences another variable. Choice C is incorrect as the independent variable is intentionally manipulated by the researcher. Choice D is incorrect as it refers to a different concept unrelated to the independent variable in an experiment.

Correct Answer: C

Rationale: Critics worry that fetal monitoring may identify babies as in danger who, in fact, are not. This can lead to unnecessary interventions and stress for the parents. It is important to carefully consider the accuracy and benefits of fetal monitoring to avoid unnecessary harm to both the mother and the baby. Choice A is incorrect because fetal monitoring does not cause numbness in the lower half of the body. Choice B is incorrect as fetal monitoring is helpful in detecting hidden problems with the baby. Choice D is incorrect as there is no direct link between fetal monitoring and an increased likelihood of infant brain damage.

Correct Answer: D

Rationale: Lanugo helps the vernix stick to the skin. Vernix is a waxy substance that covers the fetus's skin during pregnancy. Lanugo is a fine, downy hair that helps to anchor the vernix to the skin, providing protection and nourishment to the developing fetus. Choices A, B, and C are incorrect as they do not accurately describe the role of lanugo in prenatal development.

Correct Answer: D

Rationale: Taking tests and answering questionnaires are examples of research methods. Research methods refer to the specific approaches used in conducting research, such as collecting data, analyzing information, and drawing conclusions. In this case, tests and questionnaires are tools used to gather information and data for research purposes, making them examples of research methods. Choices A, B, and C are incorrect because research designs refer to the overall structure and plan of a study, theories are explanations developed through research and observation, and hypotheses are specific predictions or statements that can be tested through research.

Correct Answer: C

Rationale: In field experiments, researchers randomly assign participants to treatment conditions in natural settings. This method allows for a higher level of control over potential confounding variables compared to non-random assignment. Random assignment helps ensure that the groups being compared are comparable at the beginning of the study, which strengthens the internal validity of the research findings. Choice A is incorrect because selective assignment may introduce bias. Choice B is incorrect as researchers can use random assignment in field experiments. Choice D is incorrect because field experiments typically have less control over the treatment compared to laboratory experiments.