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 man can row his boat with the stream at 16 km / h and against the stream in 12 km / h . the man ' s rate is ? 
Options: a ) 8 kmph , b ) 9 kmph , c ) 2 kmph , d ) 4 kmph , e ) 1 kmph
Example Output: c

Example Input: Problem: ramu bought an old car for rs . 42000 . he spent rs . 13000 on repairs and sold it for rs . 60900 . what is his profit percent ? 
Options: a ) 10.7 % , b ) 19 % , c ) 18 % , d ) 14 % , e ) 16 %
Example Output: a

Example Input: Problem: what will be the compound interest on a sum of rs . 25,000 after 3 years at the rate of 12 % p . a . ? 
Options: a ) rs . 10123.77 , b ) rs . 10123.21 , c ) rs . 10123.20 , d ) rs . 10123.28 , e ) rs . 10123.21
Example Output:
c