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: a shop owner professes to sell his articles at certain cost price but he uses false weights with which he cheats by 30 % while buying and by 10 % while selling . what is his percentage profit ? 
Options: a ) 10.22 % , b ) 20.22 % , c ) 21.22 % , d ) 30 % , e ) ca n ' t be calculated
Example Output: d

Example Input: Problem: the difference between c . i . and s . i . on an amount of rs . 15,000 for 2 years is rs . 24 . what is the rate of interest per annum ? 
Options: a ) 8 , b ) 2 , c ) 9 , d ) 4 , e ) 6
Example Output: d

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 . 27000 . a ' s share is ? 
Options: a ) 9000 , b ) 2778 , c ) 6000 , d ) 2889 , e ) 6612
Example Output:
a