A consumer price index of 100 in 2020 with a base year of 2019 would mean that:
A. The cost of the market basket fell (in terms of its opportunity cost) from the cost of the market basket in 2019
B. Rose 0% from the cost of the market basket in 2019
C. Rose 100% from the cost of the market basket in 2019
D. Fell 100% from the cost of the market basket in 2019