If We Observe That the Actual Overnight Interest Rate Has

If we observe that the actual overnight interest rate has fallen, we can definitely conclude that the

A) Government of Canada has reduced the money supply.
B) Bank of Canada has abandoned its inflation target.
C) Bank of Canada has implemented a contractionary monetary policy.
D) Bank of Canada has implemented an expansionary monetary policy.
E) -- it is not possible to conclude any of the above.