The Fed's Purchase of U.S.government Securities Constitutes A(n)

The Fed's purchase of U.S.government securities constitutes a(n) :

A) contractionary policy because it lowers the amount of total reserves in the banking system.
B) contractionary policy because it lowers the amount of excess reserves in the banking system.
C) expansionary policy because it raises the amount of total reserves in the banking system.
D) expansionary policy because it lowers the amount of total reserves in the banking system.
E) expansionary policy because it raises the amount of required reserves in the banking system.