This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain , Subject name: Anatomy
[{'content': 'In the postnatal period the greatest growth in the grey matter of the C.N.S. is of \nSelect and explain. \nA. Length of Axon, B. Neuron cell number, C. Dendritic tree, D. Size of Perikaryon', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The brain of newborn weighs approximately 300-350g. By 12 months, it reaches about two-thirds of adult brain. The postnatal growth of cerebral hemispheres results mainly from myelination. Myelination continues long after gray matter has reached a specific volume.', 'role': 'assistant'}]