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': "Bacteria in plaque are held together by \nSelect and explain. \nA. Hydrophobic forces, B. Covalent bonds, C. Vander waal's forces, D. All of the above", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]