Concept:Monetary control is the use of central bank tools to regulate the money supply, credit, and interest rates in an economy.
Explanation:The Central Bank of Nigeria has several techniques of monetary control, including open market operations, cash reserve ratio, and selective credit control.
Selective credit control is a direct method of limiting or directing credit to boost productive sectors.
It is one of the main techniques used by the central bank for monetary control.
A budget deficit is a fiscal policy measure of the government, not a central bank technique.
Foreign exchange control deals with the regulation of foreign currency transactions and is not classified among the standard monetary control instruments.
Monitoring the general price level is a policy goal, not a tool for regulating money supply.
Thus, the central bank technique listed in the options is selective credit control.
Answer:A. selective credit control