Task: Question Answering
Input (English): Problem: a sum of money becomes 7 / 6 of itself in 6 years at a certain rate of simple interest . the rate per annum is ? 
Options: a ) 50 / 9 , b ) 50 / 13 , c ) 50 / 17 , d ) 25 / 9 , e ) 5 5 / 1
Output (English): d