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: a survey was sent to 95 customers , 7 of whom responded . then the survey was redesigned and sent to another 63 customers , 9 of whom responded . by approximately what percent did the response rate increase from the original survey to the redesigned survey ? 
Options: a ) 2 % , b ) 5 % , c ) 7 % , d ) 28 % , e ) 63 %
Example Output: c

Example Input: Problem: at a particular graduation party with 300 guests , 70 % of the guests brought gifts , and 40 % of the female guests brought gifts . if 30 males did not bring gifts to the party , how many females did bring gifts ? 
Options: a ) 18 , b ) 28 , c ) 40 , d ) 68 , e ) 70
Example Output: c

Example Input: Problem: 60 is increased by 50 % . find the final number . 
Options: a ) 100 , b ) 110 , c ) 90 , d ) 30 , e ) 160
Example Output:
c