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 6 km / h and against the stream in 3 km / h . the man ' s rate is ?
Options: a ) 1.5 kmph , b ) 3 kmph , c ) 8 kmph , d ) 7 kmph , e ) 5 kmph
Example Output: a

Example Input: Problem: if 20 % of a number = 1000 , then 120 % of that number will be ?
Options: a ) 20 , b ) 120 , c ) 360 , d ) 6000 , e ) 820
Example Output: d

Example Input: Problem: a shopkeeper sells 20 % of his stock at 20 % profit ans sells the remaining at a loss of 10 % . he incurred an overall loss of rs . 500 . find the total worth of the stock ?
Options: a ) 13500 , b ) 12000 , c ) 12500 , d ) 15000 , e ) 15500
Example Output:
c