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': 'RPD is indicated in all except \nSelect and explain. \nA. Long edentulous span, B. Multiple edentulous spaces, C. Excessive loss of alveolar bone, D. Distal abutment Loss', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]