A 6-month-old girl is brought to the emergency department with fever (38.5°C), productive cough, and tachypnea (48 breaths/min). Her parents report recurrent episodes of sinusitis and otitis media since 2 months of age. Physical examination reveals decreased breath sounds in the right lower lobe. Chest X-ray demonstrates a right-sided heart silhouette with left lower lobe consolidation. On careful examination, the liver edge is palpable below the left costal margin, and the spleen is felt on the right side. The patient has normal nasal passages without polyps. Which of the following embryologic abnormalities best explains this clinical presentation?

1. A)Failure of the notochord to regress, resulting in persistence of midline structures
2. B)Defective ciliary dynein arms leading to impaired mucociliary clearance and randomized organ lateralityGABARITO
3. C)Neural crest cell migration failure affecting branchial arch derivatives
4. D)Abnormal mesodermal segmentation during somite formation
5. E)Failure of the foregut to properly separate into respiratory and digestive components