For the Gold Standard to Achieve Its Maximum Functioning Efficiency,central

For the gold standard to achieve its maximum functioning efficiency,central banks should theoretically play the "rules of the game." What are these rules?

A) Central bank policy should tie the flow of their gold reserves to their current accounts.
B) Central banks should "lean against the wind" and follow policies that offset gold movements.
C) Central banks should raise interest rates as gold flows in and lower them as gold flows out.
D) Central banks should sell securities as gold flows in and buy them as gold flows out.