Correct Answer: B

Rationale: By the end of Greta's first month of pregnancy, her embryo is about ¼ inch long. During the first month of pregnancy, the embryo is in the very early stages of development, and its size is typically around ¼ inch as it continues to grow and develop in the uterus. Choices A, C, and D are incorrect because sensory abilities like sensing the world, sucking thumb, and curling toes develop later in the pregnancy as the embryo progresses through different stages of development.

Correct Answer: C

Rationale: Medical control over childbirth is largely responsible for the worldwide rise in cesarean deliveries. Cesarean deliveries are often performed due to various medical interventions such as monitoring the progress of labor, fetal distress, and other complications that may arise during childbirth. The increasing use of medical interventions and technology has contributed to the higher rate of cesarean deliveries globally. Choices A, B, and D are incorrect because they do not directly involve the decision-making and interventions typically carried out by medical professionals during childbirth, which are major factors leading to the rise in cesarean deliveries.

Correct Answer: B

Rationale: Ethnographies reveal that immigrant parents prioritize education as the surest way to improve life chances for their children. While learning English is important for integration, education is considered the key for better opportunities and success in the long term. Close ties to an ethnic community can provide support but may not directly lead to improved life chances. Moving into an urban area is not highlighted in the context of immigrant parents' views on improving life chances through their children's development.

Correct Answer: D

Rationale: When children are research participants, it is essential to obtain informed consent from their parents or others who act on their behalf. This is to ensure that the child's rights and well-being are protected during the research process. Informed consent is a fundamental ethical principle in research involving children, as they may not have the capacity to fully understand the implications of their participation. Choice A is incorrect because seeking the opinion of others when in doubt about harmful effects is not a substitute for informed consent. Choice B is incorrect because children do not have an absolute right to conceal their identity in research, especially when it comes to ensuring their safety and well-being. Choice C is incorrect as it is important to inform children or their parents about the results of the research to maintain transparency and respect for their participation.

Correct Answer: D

Rationale: Quiet alertness is indeed the most fleeting state of arousal. This state is characterized by a newborn infant being awake, calm, and attentive, but it is short-lived and transitions quickly to other states of arousal. Regular sleep, REM sleep, and drowsiness are not considered as brief and transitional as quiet alertness in newborn infants.