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: Psychiatry
[{'content': 'A child with schizophrenia was on medications. Suddenly he developed neck stiffness & spasm. What is most probable cause? \nSelect and explain. \nA. Conversion disorder, B. Acute dystonia, C. Akathisia, D. Tardive dyskinesia', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is'b'i.e., Acute dystonia[Ref: Kaplan & sadock's p 992", 'role': 'assistant'}]