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: Dental
[{'content': 'Apexification is done with \nSelect and explain. \nA. Ca(OH)2 at the apex, B. Ca(OH)2 direct pulp capping, C. Indirect pulp capping, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]