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: by selling 10 pencils for a rupee a man loses 15 % . how many for a rupee should he sell in order to gain 15 % ? 
Options: a ) 8.39 , b ) 6.39 , c ) 7.39 , d ) 9.39 , e ) 2.39
Example Output: c

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: what is the rate percent when the simple interest on rs . 910 amount to rs . 260 in 4 years ? 
Options: a ) 7.14 , b ) 6.14 , c ) 5.14 , d ) 3.14 , e ) 2.14
Example Output:
a