Answer:
The correct answer is letter "D": buying and selling of securities (primarily Treasury bonds).
Explanation:
The Federal Open Market Committee or FOMC is a department of the Federal Reserve Board in charge of establishing monetary policy. There are different meetings within a year they held to determine to continue with the current policy or to change it. A change in monetary policy represents the purchase or sale of government securities (treasury bonds) on the open market to stimuli the economy.