Correct Answer: C

Rationale: Dr. George's prediction that positive reinforcement would increase prosocial behavior in preschoolers is an example of a hypothesis. A hypothesis is a specific, testable prediction about the relationship between variables based on existing knowledge or theories. In this case, Dr. George is making a prediction about the effect of positive reinforcement on prosocial behavior, which can be tested through research. Choice A, 'theory,' is incorrect because a theory is a broader explanation that integrates a range of findings and observations. Choice B, 'research question,' is incorrect as it refers to an inquiry that asks about the relationship between variables but lacks the specificity and testability of a hypothesis. Choice D, 'research design,' is incorrect as it pertains to the overall strategy or plan for conducting a research study, not the specific prediction Dr. George made.

Correct Answer: B

Rationale: Passive smoking, also known as secondhand smoke, can have harmful effects on pregnancies. Research has shown that exposure to smoke-filled environments during pregnancy is linked to low birth weight, infant death, and childhood respiratory illnesses. Pregnant women should avoid exposure to secondhand smoke to protect the health of their unborn babies. Choice A is incorrect because passive smoking affects both the mother and the unborn child, not just children born to heavy smokers. Choice C is incorrect as it underestimates the risks of smoke-filled environments on unborn children. Choice D is incorrect as research has already established the harmful effects of passive smoking on pregnancies.

Correct Answer: C

Rationale: The correct answer is C: longitudinal. In a longitudinal design, participants are followed and studied over an extended period, allowing researchers to observe changes and continuity in development as individuals age. This design is crucial for understanding how individuals grow and change over time. Cross-sectional studies (Choice A) involve comparing different groups at the same time point, while experimental studies (Choice B) involve manipulating variables to observe their effects. Correlational studies (Choice D) examine relationships between variables but do not involve studying participants over time.

Correct Answer: B

Rationale: The correct answer is the third month of pregnancy (choice B). During the third month of pregnancy, which is around 9-12 weeks, a fetal heartbeat can typically be heard using a stethoscope. This is an exciting milestone for expectant parents as it provides reassurance about the baby's well-being. Choices A, C, and D are incorrect because by the fourth week of pregnancy, the fetal heartbeat is not usually detectable with a stethoscope. The end of the second trimester and the beginning of the third trimester are too late in the pregnancy timeline for this milestone.

Correct Answer: C

Rationale: During the last half of the first month of pregnancy, the nervous system develops the fastest among the options provided. This rapid development of the nervous system is crucial for the overall growth and functioning of the fetus. The nervous system includes the brain and spinal cord, which are essential for various bodily functions and will continue to develop throughout the pregnancy. The circulatory system, although important, does not develop at the fastest rate during this stage. The endocrine system and skin also play significant roles in the development of the fetus but are not the systems that develop the fastest in the last half of the first month of pregnancy.