The annual inflation rate over those years can be calculated using the formula:
Inflation rate = ((Price level in year 2 - Price level in year 1) / Price level in year 1) x 100%
Using the given information, we can calculate the inflation rate for each year:
Inflation rate from year 1 to year 2 = ((120 - 100) / 100) x 100% = 20%
Inflation rate from year 2 to year 3 = ((140 - 120) / 120) x 100% = 16.67%
The annual inflation rate over those three years would not remain the same, as it is increasing each year.
Therefore, the correct answer is that the annual inflation rate over those years would increase.