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 16 pencils for a rupee a man loses 28 % . how many for a rupee should he sell in order to gain 28 % ? 
Options: a ) 8 , b ) 9 , c ) 7 , d ) 6 , e ) 4
Example Output: b

Example Input: Problem: if a radio is purchased for rs 490 and sold for rs 465.50 find the loss % ? 
Options: a ) 5 % , b ) 4 % , c ) 6 % , d ) 8 % , e ) 7 %
Example Output: a

Example Input: Problem: 2 is what percent of 40 ? 
Options: a ) 0.2 % , b ) 2 % , c ) 5 % , d ) 20 % , e ) 500 %
Example Output:
c