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: the current birth rate per certain number of people is 52 , whereas corresponding death rate is 16 per same number of people . if the net growth rate in terms of population increase is 1.2 percent , find number of persons . ( initally ) 
Options: a ) 4000 , b ) 2000 , c ) 3000 , d ) 5000 , e ) 1000
Example Output: c

Example Input: Problem: a , b and c enter into partnership . a invests some money at the beginning , b invests double the amount after 6 months , and c invests thrice the amount after 8 months . if the annual gain be rs . 21000 . a ' s share is ? 
Options: a ) 2999 , b ) 2778 , c ) 7000 , d ) 2889 , e ) 6612
Example Output: c

Example Input: Problem: what will be the fraction of 10 % 
Options: a ) 1 / 10 , b ) 1 / 50 , c ) 1 / 75 , d ) 1 / 25 , e ) none of these
Example Output:
a