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': "Macromolecules in Dental Resin is attached by: \nSelect and explain. \nA. Covalent bonds, B. Sonic bonds, C. Vander Wall's Forces, D. Hydrogen Bonds", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]