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: in how many years rs 160 will produce the same interest at 8 % as rs . 500 produce in 4 years at 8 % 
Options: a ) 13 , b ) 13.5 , c ) 11.5 , d ) 12.5 , e ) 12
Example Output: d

Example Input: Problem: exactly 5 % of the reporters for a certain wire service cover local politics in country x . if 30 % of the reporters who cover politics for the wire service do not cover local politics in country x , what percent of the reporters for the wire service do not cover politics ? 
Options: a ) 20 % , b ) 42 % , c ) 44 % , d ) 92 % , e ) 90 %
Example Output: d

Example Input: Problem: 20 litres of mixture contains 20 % alcohol and the rest water . if 3 litres of water be mixed with it , the percentage of alcohol in the new mixture would be ? 
Options: a ) 16.67 % , b ) 23 % , c ) 18.3 % , d ) 19.75 % , e ) 17.4 %
Example Output:
e