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: sheela deposits rs . 5000 in bank savings account . if this is 20 % of her monthly income . what is her monthly income in ? 
Options: a ) 22000 , b ) 20000 , c ) 25000 , d ) 22235 , e ) none of these
Example Output: c

Example Input: Problem: a shopkeeper sells 500 metres of cloth for rs . 18000 at a loss of rs . 5 per metre . find his cost price for one metre of cloth ? 
Options: a ) 12 , b ) 27 , c ) 29 , d ) 50 , e ) 41
Example Output: e

Example Input: Problem: what will be the compound interest on a sum of rs . 21,000 after 3 years at the rate of 12 % p . a . ? 
Options: a ) rs . 8503.49 , b ) rs . 9720 , c ) rs . 10123.20 , d ) rs . 10483.20 , e ) none
Example Output:
a