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': 'Which of the following procedures is least successful in\nresolving a periodontally related osseous defect \nSelect and explain. \nA. Osseous coagulum graft, B. Resection surgery, C. Reattachment procedure, D. Alloplast graft', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]