Answer:
d. 11.1 percent inflation between Years 1 and 2, and 5 percent deflation between Years 2 and 3.
Explanation:
Inflation Rate between Current Year and Previous Year = ((Price Index in Current Year - Price Index in Previous Year) / Price Index in Previous Year) * 100
Inflation Rate between Year 2 and Year 1 = ((Price Index in Year 2 - Price Index in Year 1) / Price Index in Year 1) * 100 = ((100 - 90) / 90) * 100 = +11.1111%
Inflation Rate between Year 3 and Year 2 = ((Price Index in Year 3 - Price Index in Year 2) / Price Index in Year 2) * 100 = ((90 - 100) / 100) * 100 = -5%
*Negative value = Deflation