Suppose that U$.$S$.$ debt is $$7$ trillion at the beginning of the fiscal year. During the fiscal year, its purchases of goods and services and its transfers are $$1$ trillion, and tax revenues are $$1\mathrm{.}5$ trillion. At the end of the fiscal year, the debt is $:

$9$ trillion.

$10\mathrm{.}5$ trillion.

$7\mathrm{.}5$ trillion.

$6\mathrm{.}5$ trillion.