Correct Answer: A

Rationale: The correct answer is A. Positioning the car seat at a 45-degree angle is crucial to prevent the baby's head from falling forward, which can obstruct the airway. Choice B is incorrect because the recommendation is to keep the car seat rear-facing until the baby reaches the height or weight limit set by the car seat manufacturer, typically beyond 12 months. Choice C is incorrect as the harness should be snugly placed at or below the baby's shoulders, not above. Choice D is incorrect as the retainer clip should be positioned at armpit level to secure the harness straps properly.

Correct Answer: A

Rationale: A zygote is the correct answer. It is the initial cell formed when a sperm cell fertilizes an egg cell, marking the beginning of human development. Choice B, gonadotrope, is incorrect as it refers to a type of hormone-secreting cell in the pituitary gland. Choice C, embryo, is incorrect as it is the stage of development after the zygote has implanted into the uterine wall and undergone initial cell divisions. Choice D, chromaffin, is incorrect as it refers to cells found in the adrenal medulla that produce and store catecholamines.

Correct Answer: D

Rationale: The correct answer is D: Absent patellar reflexes. Absent patellar reflexes can indicate magnesium toxicity, a serious condition that requires immediate intervention to prevent respiratory depression or cardiac arrest. Dizziness while standing (choice A) is common in pregnancy but does not specifically indicate magnesium toxicity. Sinus tachycardia (choice B) can be a normal response to magnesium sulfate but does not indicate toxicity. Lower back pain (choice C) is common in pregnancy and not specifically associated with magnesium toxicity.

Correct Answer: D

Rationale: Reassuring the mother that the baby's urine color can be an indicator of adequate hydration can help her feel more confident in her breastfeeding.

Correct Answer: C

Rationale: Hypnosis can be an effective method of pain control during labor, especially if practiced during the prenatal period. Choice A is not specific to hypnosis and may not be directly related. Choice B is not essential for hypnosis and may not always be required. Choice D is incorrect as hypnosis has been shown to be beneficial for managing labor pain when done correctly, making it an inappropriate option to include in the teaching.