If the economy slows down in response to a some shock that has caused household and firms to demand less at current price levels, macroeconomic policy makers MUST respond - they must do something - or the economy will never return to its potential, steady-state output.

A. False. Whether policy makers respond or not, the invisible hand will start doing its thing to - eventually - bring the economy back to potential output.

B. Without policy changes that affect supply and demand, there is no hope. The economy is stuck until another shock - good or bad - comes along and changes things again.