(b) A change in the policy rate can be categorized via the optimal rate rule in terms the change in inflation as follows: . expansionary if the new rate is lower than what the change in inflation indi- cated. . contractionary if the new rate is higher than what the change in inflation indicated. . neither expansionary or contractionary if the new rate is what the change in inflation indicated. If there was no change in inflation when the PBOC changed the reverse-repo rate, was their action expansionary, contractionary, or neither? Briefly explain