Task: Question Answering
Input (English): Question: If money is invested at r percent interest, compounded annually, the amount of investment will double in approximately 70/r years. If Pat's parents invested $ 8000 in a long term bond that pays 8 percent interest, compounded annually, what will be the approximate total amount of investment 18 years later, when Pat is ready for college?

 Option A: $20000

 Option B: $15000

 Option C: $32000

 Option D: $10000

 Option E: $9000
Output (English): Option C