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: a merchant gets a 5 % discount on each meter of fabric he buys after the first 2,000 meters and a 7 % discount on every meter after the next 1,500 meters . the price , before discount , of one meter of fabric is $ 2 , what is the total amount of money the merchant spends on 7,000 meters of fabric ? 
Options: a ) $ 13,360 , b ) $ 14,450 , c ) $ 15,720 , d ) $ 16,780 , e ) $ 17,240
Example Output: a

Example Input: Problem: a $ 500 investment and a $ 1,500 investment have a combined yearly return of 16 percent of the total of the two investments . if the $ 500 investment has a yearly return of 7 percent , what percent yearly return does the $ 1,500 investment have ? 
Options: a ) 9 % , b ) 10 % , c ) 105 / 8 % , d ) 11 % , e ) 19 %
Example Output: e

Example Input: Problem: a chemical supply company has 60 liters of a 25 % hno 3 solution . how many liters of pure undiluted hno 3 must the chemists add so that the resultant solution is a 50 % solution ? 
Options: a ) 12 , b ) 15 , c ) 20 , d ) 24 , e ) 30
Example Output:
e