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 merchant sells an item at a 20 % discount , but still makes a gross profit of 20 percent of the cost . what percent p of the cost would the gross profit on the item have been if it had been sold without the discount ? 
Options: a ) 20 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 75 %
Example Output: c

Example Input: Problem: the profit earned by selling an article for $ 832 is equal to the loss incurred when the same article is sold for $ 448 . what should be the sale price for making 35 % profit ? 
Options: a ) $ 480 , b ) $ 450 , c ) $ 960 , d ) $ 864 , e ) $ 660
Example Output: d

Example Input: Problem: if 15 % of 30 % of 50 % of a number is 99 , then what is the number ? 
Options: a ) 4000 , b ) 3050 , c ) 4400 , d ) 4500 , e ) none of these
Example Output:
c