The term "automatic stabilizers" refers to the fact that: （）
A. with given tax rates and expenditure policies, a rise in national income tends to produce a surplus, while a decline tends to result in a deficit.
B. legislators automatically change the tax structure and expenditure programs to correct upswings and downswings in business activity.
C. government expenditures and tax receipts automatically balance over the course of the business cycle, although they may be out of balance in any single year.
