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': 'Irresistible urge to do a thing repeatedly is seen in- \nSelect and explain. \nA. Obsessive - compulsive disorder, B. Schizophrenia, C. Schizoaffective disorder, D. Depression', 'role': 'user'}, {'content': 'Answer: A \nExplanation: OCD is an anxiety disorder, which is characterized by recurrent, unwanted thoughts (obsessions) and repetitive behaviors (compulsion).', 'role': 'assistant'}]