The figure above shows the market for bank reserves in Futureland. If the Bank of Futureland undertakes an open market purchase of government securities that changes the quantity of reserves by $25 billion, then the federal funds rate will

A) fall to 4 percent a year.
B) remain at 6 percent a year.
C) rise to 8 percent a year.
D) change, but more information is needed to determine by how much.
E) None of the above answers is correct.