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: Biochemistry
[{'content': 'In lac operon, transcription is inhibited by binding into ? \nSelect and explain. \nA. Promotor site, B. Operator site, C. CAP site, D. None of the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Operator siteRepressor binds to this site and blocks transcription.", 'role': 'assistant'}]