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: after decreasing 40 % in the price of an article costs rs . 1050 . find the actual cost of an article ? 
Options: a ) 1200 , b ) 1750 , c ) 1050 , d ) 1570 , e ) 1005
Example Output: b

Example Input: Problem: a man buys an article for $ 10 . and sells it for $ 30 . find the gain percent ? 
Options: a ) 25 % , b ) 50 % , c ) 20 % , d ) 150 % , e ) 300 %
Example Output: e

Example Input: Problem: find the simple interest on $ 6000 at 15 % per annum for 9 months ? 
Options: a ) $ 492 , b ) $ 512 , c ) $ 675 , d ) $ 745 , e ) $ 1020
Example Output:
c