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: sarah operated her lemonade stand monday through friday over a two week period and made a total profit of 210 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 3 of the days were hot , then what was the price of 1 cup on a hot day ? 
Options: a ) $ 1.50 , b ) $ 1.64 , c ) $ 2.25 , d ) $ 2.50 , e ) $ 3.25
Example Output: b

Example Input: Problem: a sum fetched a total simple interest of 4034.25 at the rate of 9 % . p . a . in 5 years . what is the sum ? 
Options: a ) 5768 , b ) 8925 , c ) 8965 , d ) 6474 , e ) 8723
Example Output: c

Example Input: Problem: if the compound interest on a certain sum of money for 3 years at 10 % per annum be rs . 993 , what would be the simple interest ? 
Options: a ) rs . 880 , b ) rs . 890 , c ) rs . 895 , d ) rs . 900 , e ) none
Example Output:
d