Correct Answer: D

Rationale: Lanugo helps the vernix stick to the skin. Vernix is a waxy substance that covers the fetus's skin during pregnancy. Lanugo is a fine, downy hair that helps to anchor the vernix to the skin, providing protection and nourishment to the developing fetus. Choices A, B, and C are incorrect as they do not accurately describe the role of lanugo in prenatal 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: Piaget's critics point out that his stagewise account pays insufficient attention to social and cultural influences. Critics argue that Piaget's theory does not fully consider the impact of social interactions, cultural differences, and individual experiences on children's cognitive development. They believe that these factors play a crucial role in shaping a child's thinking and problem-solving abilities, which should be given more emphasis. Choice A is incorrect because Piaget's critics do not focus on him overestimating the competencies of infants and young children. Choice C is incorrect as it discusses a different aspect of learning rather than the critique of Piaget's theory. Choice D is also incorrect since critics do not argue that children's performances on Piagetian tasks cannot be improved with training.

Correct Answer: C

Rationale: Max, age 65, learning to play the piano at a local senior center demonstrates that development is plastic at all ages. This means that individuals have the potential to learn and grow regardless of their age, showing that it is never too late to acquire new skills and experiences. Choice A is incorrect because it presents a negative view of aging, which is not supported by Max's actions. Choice B is incorrect as it implies that learning is restricted to certain age periods, which is contradicted by Max's experience. Choice D is incorrect because Max's learning of the piano at 65 suggests that musical talent can be developed at any age, not necessarily peaking in late adulthood.

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.