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'.

Input: Consider Input: Problem: a reduction of 20 % in the price of salt enables a lady to obtain 10 kgs more for rs . 400 , find the original price per kg ? 
Options: a ) s . 7 , b ) s . 9 , c ) s . 10 , d ) s . 11 , e ) s . 19

Output: c


Input: Consider Input: Problem: find the principle on a certain sum of money at 5 % per annum for 4 years if the amount being rs . 1120 ? 
Options: a ) 933 , b ) 1067 , c ) 1977 , d ) 1056 , e ) 1097

Output: a


Input: Consider Input: Problem: a man sold 20 articles for $ 40 and gained 20 % . how many articles should he sell for $ 90 to incur a loss 20 % ? 
Options: a ) 45 , b ) 36 , c ) 40 , d ) 50 , e ) 67.5


Output: e