Task: Question Answering
Input (English): Problem: the ratio between the sale price and the cost price of an article is 9 : 5 . what is the ratio between the profit and the cost price of that article ? 
Options: a ) 23 , b ) 1 : 2 , c ) 4 : 5 , d ) 3 : 5 , e ) 25
Output (English): c