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 shopkeeper sold 50 articles at the cost price of 60 articles . then find the profit % or lost % 
Options: a ) 20 % , b ) 22 % , c ) 25 % , d ) 30 % , e ) 35 %
Example Output: a

Example Input: Problem: a reduction of 40 % in the price of bananas would enable a man to obtain 64 more for rs . 40.00001 , what is reduced price per dozen ? 
Options: a ) 6 , b ) 5 , c ) 4 , d ) 3 , e ) 2
Example Output: d

Example Input: Problem: if a and b get profits of rs . 5,000 and rs . 2,000 respectively at the end of year then ratio of their investments are 
Options: a ) 4 : 1 , b ) 1 : 4 , c ) 5 : 2 , d ) 2 : 3 , e ) 2 : 5
Example Output:
c