Correct Answer: A

Rationale: Naturalistic observation reflects the participants' everyday lives because it involves observing individuals in their natural environments without any manipulation. This allows researchers to see how people behave in real-world settings and can provide valuable insights into their typical behavior patterns. Choice B is incorrect because naturalistic observation focuses on observing behavior in its natural setting rather than comparing responses between participants. Choice C is incorrect as naturalistic observation tends to provide rich, qualitative data rather than a large amount of information in a short time. Choice D is incorrect because in naturalistic observation, participants are observed as they naturally behave, which may not always lead to an equal opportunity for all participants to display the behavior of interest.

Correct Answer: D

Rationale: The correct answer is D because investigators who study development aim to identify the factors that influence consistencies and transformations in people from conception to death. This goal encompasses various domains such as physical, cognitive, emotional, and social development, highlighting the comprehensive nature of developmental research. Choices A, B, and C are incorrect as they do not align with the overarching goal of developmental researchers, which is to understand the factors influencing individuals throughout their lifespan, rather than focusing solely on genetic factors, environmental factors related to disease, or abnormal development in specific age groups.

Correct Answer: C

Rationale: A case study would be the best method for Dr. Bigelow to study musical prodigies. In a case study, the researcher can closely examine and analyze the unique characteristics, abilities, and behaviors of individual subjects. This method allows for in-depth exploration of a specific phenomenon, making it ideal for investigating exceptional cases such as musical prodigies. Naturalistic observation involves observing subjects in their natural environment without interference, which may not provide the detailed insights needed for studying musical prodigies. Clinical interviews focus on gathering information through structured questioning, not ideal for studying unique talents. Structured interviews involve asking a set of predetermined questions, which may not allow for the depth of exploration required for studying musical prodigies.

Correct Answer: D

Rationale: Sensitivity to touch emerges early prenatally and is well-developed at birth. Newborn babies have a well-developed sense of touch, which is crucial for bonding with their caregivers and exploring their environment. This sensitivity to touch helps babies respond to comforting sensations such as gentle strokes and cuddles. Visual acuity, color vision, and depth perception are sensory capabilities that develop and mature after birth, not prenatally. While important for interacting with the environment, they are not as well-developed at birth as sensitivity to touch.

Correct Answer: B

Rationale: One challenge associated with longitudinal research is that participants may relocate or drop out of the study over time. This can result in missing data and potential biases in the findings, impacting the study's overall validity and reliability. Furthermore, it can present difficulties for researchers in accurately monitoring and analyzing changes in individuals over an extended period. Options A, C, and D are incorrect because longitudinal research can indeed allow for inferences about cause-and-effect relationships, findings can be generalized to the real world with appropriate design and sampling, and it is suitable for studying individual developmental patterns.