Task: Question Answering
Input (English): Problem: if the sides of a cube are in the ratio 7 : 3 . what is the ratio of their diagonals ? 
Options: a ) 9 : 4 , b ) 8 : 4 , c ) 7 : 4 , d ) 7 : 3 , e ) 6 : 4
Output (English): d