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: solution p is 20 percent lemonade and 80 percent carbonated water by volume ; solution q is 45 percent lemonade and 55 percent carbonated water by volume . if a mixture of pq contains 65 percent carbonated water , what percent of the volume of the mixture is p ? 
Options: a ) 20 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 80 %
Example Output: b

Example Input: Problem: how is 4 % expressed as a decimal fraction ? 
Options: a ) 0.4 , b ) 0.04 , c ) 0.004 , d ) 0.0004 , e ) 4
Example Output: b

Example Input: Problem: a small college reduced its faculty by approximately 15 percent to 195 professors . what was the original number of faculty members ? 
Options: a ) 182 , b ) 208 , c ) 224 , d ) 229 , e ) 302
Example Output:
d