Consider the following hypothetical data for the U.S. economy in 2020 (in trillions of dollars), and assume that there are no statistical discrepancies or other adjustments.

Profit..................................................................................2.8

Indirect business taxes and transfers...........................0.8

Rent...................................................................................0.7

Interest..............................................................................0.8

Wages................................................................................8.2

Depreciation.....................................................................1.3

Consumption.................................................................12.0

Exports..............................................................................1.5

Government transfer payments....................................2.0

Personal income taxes and nontax payments............1.7

Imports.............................................................................1.7

Corporate taxes and retained earnings.......................0.5

Social Security contributions.........................................2.0

Government spending....................................................3.8

a. What is gross domestic income? GDP?

b. What is gross private domestic investment?

c. What is personal income? Personal disposable income?