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: a and b invests rs . 3000 and rs . 4500 respectively in a business . if a doubles his capital after 6 months . in what ratio should a and b divide that year ' s profit ? 
Options: a ) 6 : 8 , b ) 9 : 8 , c ) 7 : 9 , d ) 9 : 5 , e ) 1 : 1
Example Output: e

Example Input: Problem: if rs . 420 amount to rs . 540 in 4 years , what will it amount to in 6 years at the same rate % per annum ? 
Options: a ) s . 575 , b ) s . 595 , c ) s . 590 , d ) s . 600 , e ) s . 585
Example Output: d

Example Input: Problem: find the principle on a certain sum of money at 5 % per annum for 6 years if the amount being rs . 1120 ? 
Options: a ) 862 , b ) 1067 , c ) 1977 , d ) 1056 , e ) 1097
Example Output:
a