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, the crude bih rate is 30 per 1000 people. The number of pregnant females is? \nSelect and explain. \nA. 150, B. 65, C. 175, D. 200', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 150 REF: Park 20th edition page 418 Crude bih rate = (Number of liver bihs in a year/ Estimated mid year population) x 1000 30 = (Live bihs/ 5000) x 1000 Live bihs = 150 (indirectly indication the number of pregnancy)', 'role': 'assistant'}]