Correct Answer: C

Rationale: Prenatally malnourished babies frequently catch respiratory illnesses. Malnourished babies have weakened immune systems, making them more susceptible to illnesses such as respiratory infections. This is a common consequence that is observed in babies who did not receive adequate nutrition during the prenatal period. Choices A, B, and D are incorrect. While malnourished babies may have feeding challenges, rejecting breast milk is not a common consequence. Enlarged hearts are not typically associated with prenatal malnutrition, and having a higher-than-average birth weight is unlikely in malnourished babies.

Correct Answer: A

Rationale: Lev Vygotsky viewed cognitive development as a socially mediated process, emphasizing the role of social interactions and cultural influences in shaping a child's cognitive development. This is in contrast to Jean Piaget, who focused more on individual interactions with the environment. Vygotsky believed that cognitive development is significantly influenced by social interactions with others, highlighting the importance of collaborative learning and cultural context. Choices B, C, and D are incorrect as they do not align with Vygotsky's perspective on cognitive development.

Correct Answer: B

Rationale: The correct answer is B: 'In South Africa, 30 percent of all pregnant women are HIV-positive.' This statement is true as South Africa has a high prevalence of HIV among pregnant women, emphasizing the need for interventions to prevent mother-to-child transmission. Choices A, C, and D are incorrect. Choice A is inaccurate as women account for more than 50% of new HIV infections globally. Choice C is misleading as the majority of new HIV infections actually occur in sub-Saharan Africa, not just developing countries. Choice D is also incorrect as without treatment, the risk of mother-to-child transmission is higher than 30%.

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: Low-level radiation, whether from industrial leakage or medical X-rays, can increase the risk of childhood cancer by potentially damaging the developing fetus's cells. Even though the risk is relatively low, it is still a significant concern that should be acknowledged and monitored closely, especially during prenatal development. Choice A is incorrect as low-level radiation can still be harmful on its own without the need to be combined with other teratogens. Choice C is incorrect because low-level radiation exposure can indeed cause lasting damage, especially in the context of childhood cancer risk. Choice D is incorrect because low-level radiation exposure, even during the last trimester, can pose risks to the developing fetus and is not considered entirely safe.