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': 'The extraction of upper first molars may be indicated: \nSelect and explain. \nA. When the removal of 4/4 provides insufficient space, B. Where they are rotated, C. When their prognosis is poor, D. When 5/5 are palatally placed', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Key concept:\nAny teeth which is having poor prognosis is indicated for extraction.', 'role': 'assistant'}]