A 2-day-old male presents with a prominent, fluid-filled sac at the lumbosacral spine noted at delivery. Vital signs show HR 145 bpm, RR 48, BP 65/42, and temperature 37.2°C. Physical examination reveals meninges and spinal cord tissue protruding through a midline vertebral defect. Neuroimaging confirms exposed neural elements without surrounding bone. The infant has intact lower extremity reflexes. Laboratory studies show normal cerebrospinal fluid parameters. A failure of which embryologic process most commonly causes this malformation?

1. A)Development of primary vertebral ossification centers
2. B)Development of the pedicle
3. C)Fusion of the vertebral archesGABARITO
4. D)Development of the body
5. E)Development of the superior articular process