Task: Question Answering
Input (English): Problem: the ratio between the sale price and the cost price of an article is 9 : 7 . what is the ratio between the profit and the cost price of that article ? 
Options: a ) 2 : 9 , b ) 2 : 7 , c ) 3 : 6 , d ) 2 : 0 , e ) 2 : 1
Output (English): b