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': 'Mushroom arch wire is used in \nSelect and explain. \nA. Beggs appliance, B. Lingual appliance, C. Straight wire appliance, D. Edgewise appliance', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Mushroom-shaped lingual arch forms\nNatural variations in facial–lingual tooth dimensions are significant enough on the lingual\xa0 aspects to require routine first-order bends. Distal to the cuspids, mesial to the molars and\xa0 sometimes at the maxillary laterals.\nFujita introduced the concept of ‘mushroom-shaped\xa0 archwire’ in conjunction with the lingual appliance.', 'role': 'assistant'}]