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'.

Example Input: Problem: in a class , if 50 % of the boys were girls , then there would be 50 % more girls than boys . what percentage of the overall class is girls ? 
Options: a ) 25 % , b ) 33.33 % , c ) 40 % , d ) 20 % , e ) 10 %
Example Output: d

Example Input: Problem: ravi and sunil are partners in a business . ravi invests rs . 20,000 for 8 months and sunil invested rs . 16000 for 10 months then after one year ratio of their profits will be 
Options: a ) 1 : 1 , b ) 2 : 3 , c ) 3 : 2 , d ) 3 : 1 , e ) 3 : 4
Example Output: a

Example Input: Problem: by selling 20 pencils for a rupee a man loses 20 % . how many for a rupee should he sell in order to gain 20 % ? 
Options: a ) 80 , b ) 60 , c ) 50 , d ) 30 , e ) 10
Example Output:
d