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: Surgery
[{'content': 'Goal of Visor osteotomy is \nSelect and explain. \nA. Increase the height of mandibular ridge for denture support, B. Reduce the bony undercut on both sides if present bilaterally, C. Reduce the bony spicules present on ridge hindering the denture placement, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]