By late 2007 the united states national debt (its total indebtedness) was around 9 trillion dollars, this is also known as:
a.)fiscal default
b.)bankruptcy
c.)the public debt
d.)reserve debt

C. Public Debt is the correct answer.

Explanation:

The money which a government owned to  the lenders is known as public debt. Other governments , individuals and businesses lend money to the government. It is also called as sovereign debt. Although public debt only includes the national debt but in some countries the debt of states and provinces is also included. It is the result of years of fiscal deficit. Fiscal deficit affects the debt and vice versa.