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 c . p of 20 books is equal to the s . p of 30 books . find his gain % or loss % ? 
Options: a ) 63.33 % , b ) 34.33 % , c ) 33.33 % , d ) 31.33 % , e ) 36.33 %
Example Output: c

Example Input: Problem: last year a certain bond price with a face value of 5000 yielded 10 % of its face value in interest . if that interest was approx 6.5 of the bond ' s selling price approx what was the bond ' s selling price ? 
Options: a ) 7692 , b ) 5325 , c ) 5351 , d ) 6000 , e ) 6154
Example Output: a

Example Input: Problem: the number which exceeds 16 % of it by 105 is : 
Options: a ) 125 , b ) 52 , c ) 58 , d ) 60 , e ) 62
Example Output:
a