Circle the correct answer.
Suppose that the index of prices received by farmers for 2015 was 0.97 and the base year of this index was 2000 . Then,
a. relative to 2015 , farm prices were $97 \%$ higher in 2000 .
b. relative to 2000 , farm prices were $3 \%$ lower in 2015.
c. relative to 2015 , farm prices were $3 \%$ lower in 2000.
d. relative to 2000 , farm prices were $97 \%$ higher in 2015 .