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': 'A casting may fail to seat on the prepared tooth due to all of the following factors except _____. \nSelect and explain. \nA. Temporary cement still on the prepared tooth after the temporary restoration has been removed., B. Proximal contact(s) of casting too heavy/tight., C. Undercuts present in prepared tooth., D. The occlusal of the prepared tooth was underreduced.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Occlusal reduction would not affect the ability to seat a casting. However, temporary cement, heavy proximal contacts, or tooth undercuts could keep the casting from seating completely.', 'role': 'assistant'}]