Suppose that a particular economy has a real GDP of 12 .0 trillion in 2004. it grows to 15.0 trillion in 2005. meanwhile, the national debt was 8.0 trillion in 2004. in 2005 the federal government ran a budget deficit of 0.8 trillion, which was totally financed by borrowing. Given the set of circumstances the national debt as a percentage has ? a. increased b. decreased c. doubled d. remain constant