Correct Answer: C

Rationale: According to research, mothers who are supported by a trained companion during childbirth have fewer birth complications and shorter labors. This support can reduce stress and anxiety levels, provide comfort and encouragement, and help the mother feel more in control during labor and delivery. Overall, having a trained companion present can contribute to a more positive childbirth experience for the mother. Choices A, B, and D are incorrect because they do not align with the research findings that specifically highlight the benefits of having a trained companion during childbirth.

Correct Answer: C

Rationale: Three-month-old Jefferson will likely listen longer to human speech compared to nonspeech sounds because infants have a natural preference for speech sounds. This preference is believed to be attributed to their biological readiness to learn language and communicate with others. Choice A is incorrect because voices are a form of human speech, which is preferred over pure tones. Choice B is incorrect as noises do not necessarily engage infants' attention as effectively as human speech. Choice D is incorrect because Jefferson is more likely to listen longer to his native language rather than a foreign language at this early age.

Correct Answer: B

Rationale: Baby Ian is demonstrating the Moro reflex. The Moro reflex is a normal newborn reflex that occurs when a baby feels like they are falling or losing support. It is characterized by arching the back, extending the legs, throwing the arms outward, and then bringing the arms in toward the body. This reflex is a primitive survival instinct that typically disappears around 6 months of age. Choice A, palmar grasp, involves the baby's fingers closing around an object when it touches their palm. Choice C, tonic neck reflex, involves the baby assuming a fencing position when their head is turned to one side. Choice D, Babinski reflex, is characterized by the fanning out and curling of the baby's toes when the sole of the foot is stroked.

Correct Answer: B

Rationale: The major strength of the clinical interview is that it can provide a large amount of information in a fairly brief period. This allows researchers to gather detailed data about an individual's thoughts, feelings, and behaviors efficiently. Choice A is incorrect because the clinical interview focuses on gathering information from individuals rather than comparing their responses. Choice C is incorrect as clinical interviews are primarily aimed at understanding individuals rather than cultures or social groups. Choice D is incorrect as it describes a strength of naturalistic observations, not clinical interviews.

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.