In real terms, the cost of government spending is measured by
A: Only the public sector output sacrificed when the government employs scarce resources.
B: Only the private sector output sacrificed when the government employs scarce resources.
C: Combining the private sector output with the public sector output sacrificed when the government employs scarce resources.
D: Subtracting private sector output from the public sector output sacrificed when the government employs scarce resources.