Task: Question Answering
Input (English): Problem: the annual interest rate earned by an investment increased by 10 percent from last year to this year . if the annual interest rate earned by the investment this year was 9 percent , what was the annual interest rate last year ? 
Options: a ) 1 % , b ) 1.1 % , c ) 8.18 % , d ) 10 % , e ) 10.8 %
Output (English): c