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: the owner of a furniture shop charges his customer 25 % more than the cost price . if a customer paid rs . 8340 for a computer table , then what was the cost price of the computer table ? 
Options: a ) rs . 6672 , b ) rs . 6727 , c ) rs . 6908 , d ) rs . 6725 , e ) rs . 6728
Example Output: a

Example Input: Problem: running at the same constant rate , 6 identical machines can produce a total of 270 bottles per minute . at this rate , how many bottles could 8 such machines produce in 4 minutes ? 
Options: a ) 648 , b ) 1800 , c ) 2700 , d ) 1440 , e ) none of these
Example Output: d

Example Input: Problem: if the cost price of 20 articles is same as the selling price of 25 articles . find the gain or loss percentage ? 
Options: a ) 20 % loss , b ) 30 % loss , c ) 40 % gain , d ) 40 % loss , e ) 50 % loss
Example Output:
a