Task: Question Answering
Input (English): Problem: the ratio of the present ages of two friends is 2 : 3 and 6 years back , the ratio was 1 : 3 . what will be the ratio of their ages after 4 years ? 
Options: a ) 1 : 4 , b ) 3 : 4 , c ) 1 : 2 , d ) 3 : 1 , e ) 3 : 2
Output (English): b