Methods of financing government spending are described by an expression called the government budget constraint, which states the following
选项：

A: the government budget deficit must equal the sum of the change in the monetary base and the change in government bonds held by the public.
B: the government budget deficit must equal the difference between the change in the monetary base and the change in government bonds held by the public.
C: the government budget deficit must equal the difference between the change in the monetary base and the change in government bonds held by the Fed.
D: the government budget deficit must equal the difference between the change in the monetary base and the change in government bonds held by the Treasury.