Answer:
b. is bigger than the sacrifice ratio for an expected change in the money supply
Step-by-step explanation:
If expectations of inflation are formed rationally, the sacrifice ratio for an unexpected change in the money supply is bigger than the sacrifice ratio for an expected change in the money supply.
The sacrifice ratio is an economic ratio which aims to measures the effect of rise and fall of inflation on the country's total production and output. When prices fall, companies are less incentivized to produce goods and may cut back on production. If people do form their expectations rationally, then the inflation inertia will be less intense than it appeared initially. But, if unexpected change happens (i.e. like an unexpected change in the money supply), then inflation inertia will be more intense. Therefore, the change in sacrifice ratio would be bigger.