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: how much 60 % of 50 is greater than 30 % of 30 ? 
Options: a ) 21 , b ) 91 , c ) 11 , d ) 17 , e ) 12
Example Output: a

Example Input: Problem: a candidate appearing for an examination has to secure 42 % marks to pass paper i . but he secured only 60 marks and failed by 20 marks . what is the maximum mark for paper i ? 
Options: a ) 110 , b ) 120 , c ) 130 , d ) 140 , e ) 190
Example Output: e

Example Input: Problem: the cost of an article is decreased by 20 % . if the original cost is $ 120 , find the decrease cost . 
Options: a ) 33 , b ) 11 , c ) 96 , d ) 36 , e ) 91
Example Output:
c