Correct Answer: D

Rationale: The correct answer is D because Down syndrome is primarily caused by trisomy of chromosome 21. This means there is an extra copy of chromosome 21, leading to the characteristic features of the syndrome. Mosaicism and translocation of chromosome 21 can also result in Down syndrome, albeit less frequently. Option A includes deletion, which is not a common cause of Down syndrome. Option B lists duplication, which is not a typical mechanism for Down syndrome. Option C includes deletion and mosaicism, but trisomy is the main cause of Down syndrome, making option D the most accurate choice.

Correct Answer: B

Rationale: The correct answer is B: Assess fetal lung maturity. Amniotic fluid analysis measures the levels of substances like surfactant, which indicates lung maturity. This helps in determining if the fetus is ready for delivery. Other choices are incorrect because amniotic fluid analysis is not primarily used to detect fetal infections (A), determine fetal position (C), or assess placental health (D). These functions are typically achieved through other diagnostic tests or imaging techniques.

Correct Answer: B

Rationale: The correct answer is B: Pneumothorax. Respiratory distress syndrome is characterized by difficulty breathing due to immature lungs in premature infants. Pneumothorax, a condition where air leaks into the chest cavity, is a common complication as the fragile lungs are prone to air leaks. Cerebral palsy (A), epilepsy (C), and fractured ribs (D) are not direct complications of respiratory distress syndrome. Pneumothorax is the most likely and common complication due to the fragility of the premature infant's lungs.

Correct Answer: C

Rationale: The correct answer is C: Protein intake of 50 g daily. In hepatic encephalopathy, reducing protein intake is crucial to prevent ammonia accumulation. Protein breakdown in the body leads to ammonia production, which worsens encephalopathy symptoms. Limiting protein intake to 50g daily helps decrease ammonia formation. Lactulose (choice A) is used to reduce ammonia absorption in the gut. Spironolactone (choice B) is a diuretic used to treat fluid retention in liver disease. Zolpidem (choice D) is a sedative and not related to managing ammonia accumulation in hepatic encephalopathy. Therefore, choices A, B, and D are incorrect for long-term management of ammonia accumulation in hepatic encephalopathy.

Correct Answer: A

Rationale: The correct answer is A: Respiratory insufficiency. Chronic traumatic diaphragmatic hernias can lead to gradual compromise of respiratory function due to herniation of abdominal contents into the chest cavity, causing compression of the lungs and reduced lung capacity. This results in symptoms such as dyspnea, cough, and chest pain. Sepsis (B) is more commonly associated with acute traumatic diaphragmatic hernias. Bowel obstruction (C) is a possible complication but typically presents with acute symptoms like abdominal pain and distension. Anemia (D) is not a common presentation of diaphragmatic hernias.