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 is 120 % of 13 / 24 of 840 ? 
Options: a ) 436 , b ) 478 , c ) 512 , d ) 546 , e ) 620
Example Output: d

Example Input: Problem: the salary of a person was reduced by 15 % . by what percent should his reduced salary be raised so as to bring it at par with his original salary ? 
Options: a ) 10 % , b ) 17.6 % , c ) 13.7 % , d ) 15.1 % , e ) 12.3 %
Example Output: b

Example Input: Problem: in 1998 the profits of company n were 10 percent of revenues . in 1999 , the revenues of company n fell by 20 percent , but profits were 12 percent of revenues . the profits in 1999 were what percent of the profits in 1998 ? 
Options: a ) 80 % , b ) 105 % , c ) 96 % , d ) 124.2 % , e ) 138 %
Example Output:
c