Inflation data of a foreign country for three years are as follows:

Index

Change in Index

Annual Rate of Inflation

January 1, 2010

150

January 1, 2011

200

50

50 / 150 = 33%

January 1, 2012

250

50

50 / 200 = 25%

January 1, 2013

330

80

80 / 250 = 32%

The cumulative three year inflation rate is:

a 45%

b 90%

c 120%

d 180%