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: a ladder 14 feet long is leaning against a wall that is perpendicular to level ground . the bottom of the ladder is 5 feet from the base of the wall . if the top of the ladder slips down 4 feet , how many feet will the bottom of the ladder slip ? 
Options: a ) 4 , b ) 5 , c ) 8 , d ) 10.72 , e ) 15

Ex Output:
d


Ex Input:
Problem: alex takes a loan of $ 5,000 to buy a used truck at the rate of 2 % simple interest . calculate the annual interest to be paid for the loan amount . 
Options: a ) 100 , b ) 150 , c ) 720 , d ) 200 , e ) 750

Ex Output:
a


Ex Input:
Problem: in an election between two candidates , one got 55 % of the total valid votes , 20 % of the votes were invalid . if the total number of votes was 7500 , what was the number of valid votes that the other candidate got ? 
Options: a ) 2800 , b ) 2700 , c ) 2100 , d ) 2500 , e ) none of these

Ex Output:

b