A 4-day-old male is brought to the pediatric clinic because of breathing difficulties and poor feeding. He coughs, chokes, and spits up milk very soon after beginning to suckle. Physical examination and radiographs reveal the presence of the most common type of tracheoesophageal fistula. The infant's defect likely resulted from which of the following?

1. A)Incomplete formation of the septum secundum
2. B)Patent thyroglossal duct
3. C)Incomplete recanalization of the larynx
4. D)Failure of the tracheoesophageal ridges to fuseGABARITO
5. E)Failure of the buccopharyngeal membrane to rupture