This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Basics of Psychiatry, Subject name: Psychiatry
[{'content': 'Which of the following is thought disorder? \nSelect and explain. \nA. Circumstantiality, B. Tangentiality, C. Prolixity, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Prolixity is a milder form of "flight of ideas". As mentioned in the text, flight of ideas can be considered as both a disorder of stream of thought and form of thought.', 'role': 'assistant'}]