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': 'Titanium is highly inert when used for dental applications such as implants, crowns. This can be attributed to \nSelect and explain. \nA. Titanium is a noble metal, B. Titanium is covered by Titanium oxide layer, C. Titanium is covered by Chromium oxide layer, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Some metals develop a thin adherent layer upon reaction with environment that makes them resistant to corrosion. Chromium oxide develops over Chromium, Titanium oxide develops over Titanium. Excellent biocompatibility of Titanium is attributed to its passive nature, which in turn is due to adherent Titanium Oxide layer.', 'role': 'assistant'}]