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': 'In a community of 5000 people crude bih rate is 30/1000. The number of pregnant females is: \nSelect and explain. \nA. 150, B. 165, C. 175, D. 200', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 150', 'role': 'assistant'}]