[求助]关于Inflation的一道题？ cause, price, higher, repeated, economic

crabgdd

Notes上的一道题，答案选C，我想知道D为什么不对？

For a demand-pull effect or a cost-push effect to cause inflation:
A. the AS curve has to shift in response to a shift of the AD curve.
B. the AD curve has to shift in response to a shift of the AS curve.
C. the cause of the shift in AD or AS must be repeated or sustained.
D. economic equilibrium must be re-established at a higher price level.

crabgdd

有点道理，就是说Inflation是个过程，但总会有个最高峰吧，那个点算不算是Reestablish呢？