9. Which of the following statements is true?
(a) Even if we know the values of the consumer price index for the years 2009 and 2010, we cannot calculate the inflation rate for 2010 if we do not know which year is the base year.
(b) If we know the base year is 2000, and if we know the value of the consumer price index for the year 1995, then we have all the information we need to calculate the inflation rate for 1995.
(c) If we know the base year is 2000, and if we know the value of the consumer price index for the year 1995, then we have all the information we need to calculate the percentage change in the cost of living between 1995 and 2000.
(d) If we know the base year is 1990, and if we know the value of the consumer price index for the year 2010, then we have all the information we need to calculate the inflation rate for 2010.