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: if an article is sold at 18 % profit instead of 9 % profit , then the profit would be $ 54 more . what is the cost price ? 
Options: a ) $ 500 , b ) $ 600 , c ) $ 700 , d ) $ 800 , e ) $ 900
Example Output: b

Example Input: Problem: ravi purchased a refrigerator and a mobile phone for rs . 15000 and rs . 8000 respectively . he sold the refrigerator at a loss of 5 percent and the mobile phone at a profit of 10 percent . overall he make a . 
Options: a ) 50 , b ) 288 , c ) 27 , d ) 200 , e ) 881
Example Output: a

Example Input: Problem: if a and b get profits of rs . 6000 and rs . 4000 respectively at the end of year the ratio of their investments are ? 
Options: a ) 1 : 4 , b ) 3 : 2 , c ) 2 : 3 , d ) 2 : 5 , e ) none of these
Example Output:
b