Correct Answer: B

Rationale: The correct answer is B: 'This test will determine the adequacy of placental perfusion.' The non-stress test is used to assess fetal well-being by monitoring the fetal heart rate in response to its own movements. It helps determine if the fetus is receiving enough oxygen and nutrients through placental perfusion. Choice A is incorrect because confirming fetal lung maturity is typically determined through tests like amniocentesis, not the non-stress test. Choice C is incorrect because detecting fetal infection is not the primary purpose of a non-stress test. Choice D is incorrect because predicting maternal readiness for labor is not the purpose of the non-stress test; it focuses on fetal well-being.

Correct Answer: D

Rationale: The correct answer is 'Positive fetal hemoglobin testing' (D). Positive fetal hemoglobin testing (Kleihauer-Betke test) indicates fetal-maternal hemorrhage, which is critical in an RH-negative mother due to the risk of isoimmunization. This condition can lead to sensitization of the mother's immune system against fetal blood cells, potentially causing hemolytic disease of the newborn in subsequent pregnancies. Reporting this finding promptly is crucial for appropriate management and interventions. Choices A, B, and C are not as critical in this scenario. While monitoring fetal heart rate and contractions is important, the detection of fetal-maternal hemorrhage takes precedence due to the serious implications it poses for the current and future pregnancies of an RH-negative mother.

Correct Answer: D

Rationale: Late decelerations are caused by uteroplacental insufficiency, resulting in fetal hypoxemia. They are considered ominous if persistent, indicating compromised oxygen supply to the fetus. Accelerations with fetal movement (Choice A) are reassuring signs of fetal well-being. Early decelerations (Choice B) are typically benign, associated with head compression during contractions. An average FHR of 126 beats per minute (Choice C) falls within the normal range for fetal heart rate and is not concerning. Therefore, the most concerning FHR finding in a laboring client is late decelerations (Choice D).

Correct Answer: A

Rationale: A fetal heart rate of 60 beats per minute is significantly below the normal range (110-160 bpm) and indicates fetal distress, requiring immediate intervention. This low heart rate can be a sign of fetal compromise or distress, necessitating urgent evaluation and intervention to ensure the well-being of the fetus. Choices B, C, and D do not indicate immediate fetal distress requiring urgent intervention. Ruptured amniotic membrane, onset of uterine contractions, and leaking amniotic fluid are important assessments but do not present an immediate threat to the fetus's life like a severely low fetal heart rate.

Correct Answer: C

Rationale: The endoderm is the correct answer. It is the innermost layer of the embryo that gives rise to organs such as the lungs, digestive system, liver, and pancreas. The neural tube (Choice A) forms the brain and spinal cord, not the lungs or digestive system. Mesoderm (Choice B) develops into structures like muscles, bones, and circulatory system, not the lungs or digestive system. The umbilical cord (Choice D) serves as a connection between the embryo and the placenta, providing nutrients and oxygen, but it is not the layer from which lungs and digestive system develop.