This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'A newborn baby has a prominent defect at the base of his spine through which his meninges and spinal cord protrude. A failure of which of the following processes is the most common cause of this type of defect? \nSelect and explain. \nA. Development of primary veebral ossification centers, B. Development of the pedicle, C. Development of the superior aicular process, D. Fusion of the veebral arches', 'role': 'user'}, {'content': 'Answer: D \nExplanation: .', 'role': 'assistant'}]