The correct option is A Sale of securities in the open market
Open Market Operations (OMOs): The OMO is sale and purchase of govt
securities and Treasury Bills by the central bank of the country. When
the central bank decides to pump money into circulation, it buys back
the govt securities, bills and bonds and when it decides to reduce money
in circulation, it sells the Govt bonds and securities. It is a most
powerful tool for monetary control.