During and After the Financial Crisis of 2007-2009,the Fed Greatly

During and after the financial crisis of 2007-2009,the Fed greatly increased the supply of reserves through three rounds of quantitative easing by

A) sales of both long-term Treasury securities and mortgage-backed securities.
B) sales of long-term Treasury securities and purchases of mortgage-backed securities.
C) purchases of both long-term Treasury securities and mortgage-backed securities.
D) purchases of long-term Treasury securities and sales of mortgage-backed securities.