input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 4-year-old child has a normal complement of primary teeth, but they are grey and exhibit extensive occlusal and incisal wear. Radiographic examination indicates extensive deposits of secondary dentin in these teeth. Most likely this condition is:   (A) Neonatal hypoplasia   (B) Amelogenesis imperfecta   (C) Cleidocranial dysplasia   (D) Dentinogenesis imperfecta
output: ['(D) Dentinogenesis imperfecta <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Neonatal hypoplasia  (B) Amelogenesis imperfecta  (C) Cleidocranial dysplasia  (D) Dentinogenesis imperfecta <> possible answers', '  A 4-year-old child has a normal complement of primary teeth, but they are grey and exhibit extensive occlusal and incisal wear. Radiographic examination indicates extensive deposits of secondary dentin in these teeth. Most likely this condition is: <> context']