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: Social & Preventive Medicine
[{'content': 'A birthday party was attented by 200 people out of which 55 people develops food poisoning. what is the attack rate \nSelect and explain. \nA. 25%, B. 27%, C. 30%, D. 35%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]