You are answering a USMLE-style medical question. Question: A 1-day-old infant is in the neonatal intensive care unit due to respiratory failure from pulmonary hypoplasia. The mother is a healthy 32-year-old woman who did not have regular prenatal exams. On physical examination, you notice low-set ears and retrognathia with abnormal extremity development. Which of the following abnormalities is associated with the most likely cause of this patient's symptoms? Options: A) Hepatosplenomegaly B) Posterior urethral valves C) Rocker bottom feet D) Duodenal atresia Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.