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: yesterday ' s closing prices of 1,980 different stocks listed on a certain stock exchange were all different from today ' s closing prices . the number of stocks that closed at a higher price today than yesterday was 20 percent greater than the number that closed at a lower price . how many of the stocks closed at a higher price today than yesterday ?
Options: a ) 484 , b ) 1080 , c ) 1,100 , d ) 1,320 , e ) 1,694
Example Output: b

Example Input: Problem: 90 students represent x percent of the boys at jones elementary school . if the boys at jones elementary make up 50 % of the total school population of x students , what is x ?
Options: a ) 134 , b ) 150 , c ) 225 , d ) 250 , e ) 500
Example Output: a

Example Input: Problem: a person lent a certain sum of money at 6 % per annum at simple interest and in 8 years the interest amounted to $ 572 less than the sum lent . what was the sum lent ?
Options: a ) 1000 , b ) 1100 , c ) 1200 , d ) 1300 , e ) 1400
Example Output:
b