at the end of fiscal year 2004, the federal debt of country C is $278,560,125,000. what is the closest estimation of this amount? express your answer in the form of a single digit times an integer power of 10.

a. 3 x 10^(-11)
b. 3 x 10^(11)
c. 2 x 10^(11)
d. 2.79 x 10^(11)