Final answer:
The level of public saving in a closed economy is $1 trillion.
Step-by-step explanation:
In a closed economy, public saving is equal to the difference between government revenue (T) and government spending (G) minus transfer payments (TR). In this case, the level of public saving can be calculated as:
Public Saving = (T - G) - TR
= ($3 trillion - $2 trillion) - $2 trillion
= $1 trillion
Therefore, the level of public saving in this closed economy is $1 trillion (option B).