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: Pediatrics
[{'content': 'True about autism – \nSelect and explain. \nA. Occurs in high economic striata, B. Normal communication, C. Starts before 2–3 years of age, D. More common in girls', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Autism \n\nAutism is a neurologic disroder characterized by -\n\n\nQualitative impairment in social interaction\nQualitative impairment in communication.\nRestricted repetitive and streotyped patterns of behaviour, interests, and activities.\n\n\nOnset of symptoms is usually before 3 years of age.\n3-5 times more common in boys, but more severe when occurs in girls.\nMore common among low socio-economic groups.\n\nClinical features\n\nImpairment in communication\nImpairment in social interaction\nInability to concentrate\nRestricted repetitive and streotypes patterns of behaviour, interests and activities.\nFailure to acquire speech.\nApproximately 75% of children with autism are mentally retarded.\nEpilepsy develops in approximately one-fifth to one-third individuals.\nHalf of autistic patients have abnormalties on EEG.', 'role': 'assistant'}]