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
Denominator of crude birth rate is 
Select and explain. 
A. Number of death children, B. Number of living children, C. Mid year population, D. Total number of crude birth
C: Mid year population
Answer: C: Mid year population 
Explanation: None