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: the calendar of the year 2028 can be used again in the year ? 
Options: a ) 2041 , b ) 1951 , c ) 2056 , d ) 1971 , e ) 1973
Example Output: c

Example Input: Problem: at an election 2 candidates are participated and a candidate got 20 % of votes and defeated by 500 . and 10 votes are invalid . find the total polled votes ? 
Options: a ) 843 , b ) 1023 , c ) 965 , d ) 413 , e ) 1245
Example Output: a

Example Input: Problem: redo ’ s manufacturing costs for sets of horseshoes include a $ 10,500 initial outlay , and $ 15 per set . they can sell the sets $ 40 . if profit is revenue from sales minus manufacturing costs , and the company producessells 500 sets of horseshoes , what was their profit ? 
Options: a ) $ 2100 , b ) $ 2000 , c ) $ 2050 , d ) $ 2070 , e ) $ 2500
Example Output:
b