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: by selling an article for $ 90 , a person gains $ 15 . what is the gain % ? 
Options: a ) 25 % , b ) 30 % , c ) 50 % , d ) 20 % , e ) 10 %
Example Output: d

Example Input: Problem: a discount electronics store normally sells all merchandise at a discount of 10 percent to 30 percent off the suggested retail price . if , during a special sale , an additional 15 percent were to be deducted from the discount price , what would be the lowest possible price of an item costing $ 260 before any discount ? 
Options: a ) $ 130.00 , b ) $ 145.60 , c ) $ 154.70 , d ) $ 182.00 , e ) $ 210.00
Example Output: c

Example Input: Problem: what profit percent is made by selling an article at a certain price , if by selling at 1 / 2 rd of that price , there would be a loss of 20 % ? 
Options: a ) 20 % , b ) 29 % , c ) 60 % , d ) 27 % , e ) 28 %
Example Output:
c