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: at an election 2 candidates are participated a candidate got 30 % of votes and defeated by 5000 votes . 100 votes are invalid . find the total polled votes ? 
Options: a ) 11520 , b ) 12600 , c ) 15000 , d ) 13560 , e ) 12560
Example Output: b

Example Input: Problem: uncle bruce is baking chocolate chip cookies . he has 36 ounces of dough ( with no chocolate ) and 12 ounces of chocolate . how many ounces of chocolate are left over if he uses all the dough but only wants the cookies to consist of 20 % chocolate ? 
Options: a ) 3 , b ) 6 , c ) 7.2 , d ) 7.8 , e ) 9
Example Output: a

Example Input: Problem: the present population of a town is 1000 . population increase rate is 25 % p . a . find the population of town before 1 years ? 
Options: a ) 800 , b ) 1500 , c ) 1000 , d ) 750 , e ) 500
Example Output:
a