Q: In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Problem: present birth rate is 32 per 1000 while death rate is 11 per 1000 . what will be the percentage increase in the rate of population ?
Options: a ) 0.21 % , b ) 21 % , c ) 0.021 % , d ) 2.1 % , e ) none of these
A:
d