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': 'In psychoanalytic terms, obsessive-compulsive disorder is fixed at - \nSelect and explain. \nA. Oedipal stage, B. Genital stage, C. Oral stage, D. Anal stage', 'role': 'user'}, {'content': 'Answer: D \nExplanation: OCD results from a regression from the oedipal phase to anal phase of psychosexual development, i.e. In OCD fixation occurs in anal stage (Note - Regression is reversion from higher level of development to lower level of development).', 'role': 'assistant'}]