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': 'Contraindications of  Cast restorations are all except: \nSelect and explain. \nA. Grossly carious tooth, B. Occlusal disharmony, C. Young patients due to high pulp chambers, D. Esthetics', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Contraindications\n\nSmall and shallow cavities.\nHigh plaque / caries indices.\nOcclusal disharmony.\nDissimilar metals.\nEsthetics.\nYoung patients due to presence of large pulp chambers.\nOld patients due to lengthy and multi step procedures.', 'role': 'assistant'}]