Time 1 / Point B: captures the "immediate" impact of the shock as it "hit" / "rolled over" the economy. In this case, it captures the impact the response of households, firms and the rest of the world to the pandemic as well as the impact of the various governments' public-health oriented regulatory responses (as opposed to the monetary and fiscal responses) (beginning end of March as both voluntary and involuntary lock-downs and "from home" arrangements began impacting the economy) Time 2 / Point C: captures the market adjustment - on its own - over time without macroeconomic policy. (There is no actual calendar time here because it is purely a thought experiment. Conceptually, how would the market adjust on its own with no fiscal (automatic or discretionary) or monetary policy intervention.)