Task: Question Answering
Input (English): Question: The annual birth and death rate in a country per 1000 are 39.4 and 19.4 respectively . the number of years R in which the population would be doubled assuming there is no emigration or immigration is

 Option A: 20

 Option B: R=25

 Option C: R=30

 Option D: R=35

 Option E: 40
Output (English): Option D