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: joe invested a certain sum of money in a simple interest bond whose value grew to $ 310 at the end of 3 years and to $ 410 at the end of another 5 years . what was the rate of interest in which he invested his sum ? 
Options: a ) 6 % , b ) 7 % , c ) 8 % , d ) 9 % , e ) 10 %

Ex Output:
c


Ex Input:
Problem: a fruit seller had some oranges . he sells 30 % oranges and still has 420 oranges . how many oranges he had originally ? 
Options: a ) 420 , b ) 600 , c ) 220 , d ) 400 , e ) none of these

Ex Output:
b


Ex Input:
Problem: if the cost price of 60 articles is equal to the selling price of 40 articles , then what is the percent profit ? 
Options: a ) 30 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 70 %

Ex Output:

c