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: reena took a loan of $ . 1200 with simple interest for as many years as the rate of interest . if she paid $ 588 as interest at the end of the loan period , what was the rate of interest ? 
Options: a ) 3.6 , b ) 7 , c ) 18 , d ) can not be determined , e ) none of these

Ex Output:
b


Ex Input:
Problem: sarah operated her lemonade stand monday through friday over a two week period and made a total profit of 350 dollars . on hot days she sold cups of lemonade for a price that was 25 percent higher than the regular days . each cup she sold had a total cost of 75 cents and sarah did not incur any other costs . if every day she sold exactly 32 cups and 4 of the days were hot , then what was the price of 1 cup on a hot day ? 
Options: a ) $ 1.50 , b ) $ 1.88 , c ) $ 2.09 , d ) $ 2.50 , e ) $ 3.25

Ex Output:
c


Ex Input:
Problem: by selling an article at rs . 500 , a shopkeeper makes a profit of 25 % . at what price should he sell the article so as to make a loss of 25 % ? 
Options: a ) s . 600 , b ) s . 480 , c ) s . 300 , d ) s . 450 , e ) s . 550

Ex Output:

c