If real GDP doubles and the GDP deflator doubles, then nominal GDP

Because of international time lags between ordering and the receipt of goods, a depreciation of a currency:

a. will not change import or export volumes for a time, since prices on orders already placed cannot be renegotiated. b. will immediately change import and export volumes, because buyers and sellers always include an opt-out clause. c. will affect import and export volumes in third countries not party to the particular transaction. d. will never change import or export volumes.

A . What is an open market operation? Who conducts them? b. What kind of open market operation would cause the money supply to contract? How does this work? When would the Fed be most likely to do this?