This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'Metopic suture usually disappears by \nSelect and explain. \nA. 2 years, B. 8 years, C. 4 years, D. 6 years', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Frontal bone ossifies\xa0in membrane.\nIt develops from\xa02 centres\xa0near frontal eminences, during\xa08th\xa0week of intrauterine life.\nAt birth, the bone is in 2 halves, separated in the midline by a suture, known as\xa0metopic suture,\xa0which soon starts to fuse.\nIt usually fuse and gets disappeared by 2 years of age.\nThe metopic suture occasionally persists\xa0in\xa03 to 8%\xa0of individuals.\nPremature closure of metopic suture is known as metopic craniosynostosis, resulting in trigonocephaly - triangle shaped head.', 'role': 'assistant'}]