Correct Answer: B

Rationale: When measuring a newborn's chest circumference, the appropriate anatomical landmark to use is the nipple line. This point is consistent and allows for accurate and standardized measurements across all newborn assessments. The sternal notch is not typically used for chest circumference measurements in newborns. The xiphoid process is located at the lower end of the sternum and is not an appropriate landmark for chest circumference measurement. The fifth intercostal space is typically used for locating the point of maximal impulse (PMI) during cardiac assessments, not for measuring chest circumference.

Correct Answer: A

Rationale: Vitamin K is typically administered in the vastus lateralis muscle of a newborn to prevent bleeding disorders. The vastus lateralis muscle is the preferred site for IM injections in infants due to its size and accessibility, allowing for easy and safe administration. The ventrogluteal and dorsogluteal sites are more commonly used in adults due to better muscle mass and less risk of injury to nearby structures. The deltoid muscle is typically used for older children and adults for IM injections, as it is a well-developed muscle suitable for injections in these populations.

Correct Answer: C

Rationale: An elevated temperature in a woman with ruptured membranes may indicate infection. Assessing the odor of the amniotic fluid can help determine if chorioamnionitis (an infection of the amniotic fluid) is present. This assessment is crucial to guide further interventions and management of the client's condition. Options A, B, and D are incorrect. Rechecking the client's temperature in 4 hours does not address the immediate concern of potential infection. Administering glucocorticoids intramuscularly is not indicated based solely on an elevated temperature. Preparing the client for an emergency cesarean section is premature and not supported by the information provided.

Correct Answer: C

Rationale: An L/S ratio of 2:1 indicates fetal lung maturity, as it signifies the presence of surfactant in the amniotic fluid, which helps with lung expansion and prevents collapse at the end of expiration. The absence of PG indicates immaturity of the fetal lungs, as PG appears in the amniotic fluid during the later stages of lung maturation. Biophysical profile scores and nonstress tests are assessments of fetal well-being and do not directly indicate fetal lung maturity. Therefore, choice C is the correct answer.

Correct Answer: C

Rationale: The indirect Coombs test is performed to detect Rh-positive antibodies in the mother's blood. In cases where the mother is Rh-negative and the baby is Rh-positive, the mother may develop antibodies against the baby's blood cells, which can lead to hemolytic disease of the newborn. Choice A is incorrect because kernicterus is a complication of severe jaundice, not directly assessed by the indirect Coombs test. Choice B is incorrect as the test aims to detect Rh-positive antibodies, not Rh-negative antibodies in the newborn's blood. Choice D is incorrect as the test is focused on detecting antibodies in the mother's blood, not the newborn's.