Sarah buys a house in 1999. She obtains a mortgage that carries an annual interest rate of 12 per cent, and makes payments of $880 per month. The CPI in 1999 is 100, in 2000 it is 110, and in 2001 it is 120. What is the inflation rate in 2001?
a. 9 per cent
b. 0.09 per cent
c. 90 per cent
d. No enough information provided