Correct Answer: A

Rationale: A 20-week-old fetus is able to be stimulated as well as irritated by sounds because by this stage of prenatal development, the fetus's auditory system is already well-developed. It can respond to external sounds and may even startle or move in reaction to loud noises.

Correct Answer: D

Rationale: The baby boomers are healthier, better educated, and financially better off than any previous mid- or late-life cohort. This generation has generally enjoyed higher levels of education, advancements in healthcare, and increased economic opportunities, leading to improved overall well-being compared to earlier generations.

Correct Answer: C

Rationale: Vision is the least-developed of the newborn baby's senses. Newborns have limited visual acuity and are not able to focus clearly on objects. Over time, their vision will improve as they grow and develop.

Correct Answer: A

Rationale: According to ecological systems theory, interactions between Marina and her child, Tyler, occur in the microsystem. The microsystem refers to the immediate social context in which an individual lives, such as interactions with family members, friends, and teachers. Marina and Tyler's interactions within their family unit would be considered part of the microsystem.

Correct Answer: C

Rationale: Dr. Whiren's study on how culture is transmitted to the next generation aligns best with the perspective of Lev Vygotsky. Vygotsky was a developmental psychologist who emphasized the importance of social interactions and cultural influences in shaping cognitive development. He believed that children learn through interactions with others and that culture plays a significant role in this learning process.