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'.

Ex Input:
Problem: by selling 12 pencils for a rupee a man loses 12 % . how many for a rupee should he sell in order to gain 18 % ? 
Options: a ) 12 , b ) 9 , c ) 10 , d ) 89 , e ) 81

Ex Output:
a


Ex Input:
Problem: an error 4 % in excess is made while measuring the side of a square . the percentage of error in the calculated area of the square is : 
Options: a ) 4.16 , b ) 5.16 , c ) 7.16 , d ) 8.16 , e ) 9.16

Ex Output:
d


Ex Input:
Problem: if $ 5,000 is invested in an account at a simple annual rate of r percent , the interest is $ 250 . when $ 17,000 is invested at the same interest rate , what is the interest from the investment ? 
Options: a ) $ 700 , b ) $ 750 , c ) $ 800 , d ) $ 850 , e ) $ 900

Ex Output:

d