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: at what rate percent of simple interest will a sum of money double itself in 22 years ? 
Options: a ) 6.54 % , b ) 4.54 % , c ) 8 . 2 % , d ) 4.94 % , e ) 5.54 %
Example Output: b

Example Input: Problem: if it is assumed that 60 percent of those who receive a questionnaire by mail will respond and 900 responses are needed , what is the minimum number of questionnaires that should be mailed ? 
Options: a ) 1300 , b ) 1350 , c ) 1400 , d ) 1450 , e ) 1500
Example Output: e

Example Input: Problem: the population of a town is 7600 . it decreases annually at the rate of 10 % p . a . what was its population 2 years ago ? 
Options: a ) 9400 , b ) 8000 , c ) 8500 , d ) 9500 , e ) 10000
Example Output:
a