In a Small,agricultural Nation,consumers Buy Only Steak and Potatoes

In a small,agricultural nation,consumers buy only steak and potatoes.In 2009,the base year,the typical consumer spent $potatoes on strawberries and $100 on steak.The price of potatoes is $1 and the price of steak is $2 in 2009.In 2009,the price of potatoes is $2 and the price of steak is $1.The CPI for 2010 is

A) 80.
B) 125.
C) 100.
D) 110.
E) 25 percent.