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: what profit percent is made by selling an article at a certain price , if by selling at 1 / 3 rd of that price , there would be a loss of 20 % ? 
Options: a ) 140 % , b ) 29 % , c ) 70 % , d ) 27 % , e ) 28 %
Example Output: a

Example Input: Problem: 40 is subtracted from 70 % of a number , the result is 30 . find the number ? 
Options: a ) 150 , b ) 997 , c ) 266 , d ) 288 , e ) 100
Example Output: e

Example Input: Problem: a part of certain sum of money is invested at 6 % per annum and the rest at 15 % per annum , if the interest earned in each case for the same period is equal , then ratio of the sums invested is ? 
Options: a ) 4 : 6 , b ) 4 : 9 , c ) 4 : 3 , d ) 5 : 2 , e ) 4 : 2
Example Output:
d