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: find the principle on a certain sum of money at 5 % per annum for 4 years if the amount being rs . 1120 ?
Options: a ) 933 , b ) 1067 , c ) 1977 , d ) 1056 , e ) 1097
Example Output: a

Example Input: Problem: a sum of money at simple interest amounts to $ 815 in 3 years and to $ 854 in 4 years . the sum is :
Options: a ) $ 153 , b ) $ 698 , c ) $ 398 , d ) $ 549 , e ) $ 675
Example Output: b

Example Input: Problem: a shop owner sells 50 mtr of cloth and gains sp of 10 mtrs . find the gain % ?
Options: a ) 25 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 70 %
Example Output:
a