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'.

Ex Input:
Problem: in how many years will a sum of money doubles itself at 12 % per annum on simple interest ?
Options: a ) 15 % , b ) 20 % , c ) 10 % , d ) 8 % , e ) 22 %

Ex Output:
d

Ex Input:
Problem: at what rate of compound interest per annum will a sum of rs . 1200 become rs . 1348.32 in 2 years
Options: a ) 3 % , b ) 4 % , c ) 5 % , d ) 6 % , e ) 7 %

Ex Output:
d

Ex Input:
Problem: a shop owner sells 60 mtr of cloth and gains sp of 10 mtrs . find the gain % ?
Options: a ) 20 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 70 %

Ex Output:
a