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': 'Dr. J. M. Eager reported the occurrence  of  brownish  colored  stains among majority of the residents in Naples which was termed as- \nSelect and explain. \nA. Denti di chiaie, B. Mottled enamel, C. Fluorosis stain, D. Colorado stain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In\xa0 1912,\xa0 McKay\xa0 found\xa0 an\xa0 article\xa0 written\xa0 by Dr. J. M. Eager in 1902\xa0 reporting the unusual occurrence\xa0 of\xa0 brownish\xa0 colored\xa0 stains among majority of the residents in Naples. Eager\xa0 had\xa0 termed\xa0 these\xa0 brownish discolorations as\xa0 "denti di chiaie".', 'role': 'assistant'}]