Correct Answer: D

Rationale: The difficulty in isolating the precise damage caused by illegal drugs during pregnancy is due to the fact that drug users often take several drugs, display other high-risk behaviors, and suffer from other stresses. This makes it challenging to identify the specific impact of each individual factor on prenatal development. Choices A, B, and C are incorrect because they do not address the complexity of the situation involving drug users during pregnancy. Most drug-using mothers refusing to participate in teratology research, the majority of babies not surviving, or drug-using mothers quitting during the first trimester do not directly explain the difficulty in isolating the precise damage caused by illegal drugs during pregnancy.

Correct Answer: C

Rationale: The major strength of the information-processing approach to development is its commitment to rigorous research methods. This approach emphasizes systematic observation, measurement, and experimentation to study cognitive development in individuals. By using rigorous research methods, researchers can gather reliable and valid data to better understand how information is processed in the human mind. This commitment to methodological rigor enhances the credibility and validity of the conclusions drawn within the information-processing approach to development. Choices A, B, and D are incorrect because the information-processing approach focuses on empirical research methods rather than the study of imagination, case study interviews, or disproving other developmental theories.

Correct Answer: A

Rationale: A rise in the baby's heart rate during pregnancy is usually followed within five seconds by a burst of motor activity. This indicates that the baby is responding to stimuli and is an important sign of healthy fetal development. A period of sleep, a rise in Liz's heart rate, or a drop in Liz's body temperature are not typically immediate responses to changes in the baby's heart rate. Sleep is less likely to be a direct response to changes in heart rate, Liz's heart rate is independent of the baby's heart rate changes, and a drop in Liz's body temperature is not a common immediate response to fetal heart rate changes.

Correct Answer: B

Rationale: Betty's ability to adapt effectively despite facing challenges during her childhood such as growing up in a rundown neighborhood, having divorced parents, and rarely seeing her father demonstrates resilience. Resilience refers to the capacity to achieve positive outcomes despite adverse circumstances. Betty's successful, happy, and healthy adulthood showcases her resilience in navigating and overcoming the threats to her development. Choice A, assimilation, does not fit the context of adapting effectively to adverse circumstances. Assimilation is a cognitive process related to incorporating new information into existing schemas. Choice C, age-graded development, refers to typical developmental changes that occur in a culture at a particular age. Choice D, multidimensional development, encompasses the idea that development is influenced by multiple factors across various dimensions, which is not directly related to Betty's ability to adapt effectively despite facing challenges.

Correct Answer: B

Rationale: The mother feels a natural urge to squeeze and push with her abdominal muscles during the second stage of labor. This stage occurs after the cervix is fully dilated and ends with the delivery of the baby. Choice A (first) is incorrect as the first stage is mainly characterized by the dilation of the cervix. Choice C (third) is incorrect as the third stage is the delivery of the placenta, and choice D (fourth) is incorrect as the fourth stage is the recovery period after childbirth.