Correct Answer: D

Rationale: Epidural analgesia is the most common approach to controlling pain during labor. It involves the administration of pain medication through a catheter placed in the epidural space of the spine, providing pain relief while allowing the mother to remain alert and participate in the birthing process. It is preferred by many women due to its effectiveness in reducing labor pain. Choices A, B, and C are incorrect as they do not directly address pain management during labor. While an anesthetic and a spinal block are forms of pain relief, epidural analgesia is specifically the most common method used for pain control during labor.

Correct Answer: C

Rationale: Observations of imprinting in animals, such as ducklings following the first moving object they see after hatching, led to the major concept of the critical period in human development. The critical period is a specific time frame during which an organism must experience certain stimuli to develop properly. This concept has been influential in understanding various aspects of human development, such as language acquisition and social attachment. Choices A, B, and D are incorrect. Adaptation refers to adjusting to the environment, equilibrium is about balance in cognitive processes, and classical conditioning is a learning process associated with behaviorism, none of which directly relate to the concept derived from imprinting observations.

Correct Answer: A

Rationale: Terrance exhibits a combination of physical abnormalities like a thin upper lip, short eyelid openings, a small head, and a smooth philtrum, along with developmental delays and cognitive impairments. These characteristics are indicative of fetal alcohol syndrome (FAS), which is caused by maternal alcohol consumption during pregnancy. FAS is a severe condition resulting from prenatal alcohol exposure and is characterized by a range of physical, cognitive, and behavioral issues. Choice A, fetal alcohol syndrome, is the correct answer as it aligns with Terrance's symptoms and the effects of maternal alcohol consumption during pregnancy. Choices B, C, and D are incorrect because they do not encompass the full spectrum of symptoms and impairments presented by Terrance, which are specific to fetal alcohol syndrome.

Correct Answer: B

Rationale: Folic acid supplementation early in pregnancy is crucial as it reduces the risk of abnormalities in the developing fetus. It is specifically known to prevent issues related to the neural tube, circulatory system, and urinary tract. Vitamin A, Vitamin D, and Vitamin C do not play the same role as folic acid in preventing these specific birth defects, making them incorrect choices.

Correct Answer: C

Rationale: The statement that is true about a blastocyst is that between the seventh and ninth days, it burrows deep into the uterine lining. This process, known as implantation, is essential for the blastocyst to establish a connection with the mother's body and receive nutrients for further development. It is a critical stage in prenatal development and sets the foundation for pregnancy. Choices A, B, and D are incorrect. A blastocyst is not a single cell but rather a structure composed of many cells. It is not a structure that feeds the developing organism; instead, it implants in the uterine lining to receive nutrients. It is not a membrane that regulates temperature but plays a crucial role in the initial stages of pregnancy by implanting in the uterus.