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: Pathology
[{'content': 'Dentinal union of two embryologically developing teeth is referred as \nSelect and explain. \nA. Gemination, B. Twinning, C. Concrescence, D. Fusion', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]