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: ritesh and co . generated revenue of rs . 1,500 in 2006 . this was 12.5 % of its gross revenue . in 2007 , the gross revenue grew by rs . 2,500 . what is the percentage increase in the revenue in 2007 ?
Options: a ) 12.5 % , b ) 20.83 % , c ) 25 % , d ) 50 % , e ) none of these
Example Output: b

Example Input: Problem: a statue is being carved by a sculptor . the original piece of marble weighed 250 kg . in the first week 30 per cent is cut away . in the second week 20 per cent of the remainder is cut away . in the third week the statue is completed when 25 percent of the remainder is cut away . what is the weight of the final statue ?
Options: a ) 105 kg , b ) 145 kg , c ) 165 kg , d ) 115 kg , e ) 100 kg
Example Output: a

Example Input: Problem: a major airplane manufacturer announced the sale of 150 small airliners at $ 125 million each , 75 medium sized airliners at $ 175 million each , and 60 large airliners at $ 220 million each . what percentage of the company ' s income came from large and medium airliners ?
Options: a ) 29 % , b ) 41 % , c ) 58 % , d ) 69 % , e ) 70 %
Example Output:
c