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 candidate got 35 % of the votes polled and he lost to his rival by 2430 votes . how many votes were cast ? 
Options: a ) 7500 , b ) 3388 , c ) 8100 , d ) 2888 , e ) 2661
Example Output: c

Example Input: Problem: a man can row his boat with the stream at 19 km / h and against the stream in 11 km / h . the man ' s rate is ? 
Options: a ) 4 kmph , b ) 2 kmph , c ) 7 kmph , d ) 8 kmph , e ) 3 kmph
Example Output: a

Example Input: Problem: a sum of money at simple interest amounts to $ 700 in 3 years and to $ 764 in 4 years . the sum is : 
Options: a ) $ 508 , b ) $ 698 , c ) $ 398 , d ) $ 549 , e ) $ 675
Example Output:
a