Assume an Economy That Is Producing Only One Product Refer to the Data

Assume an economy that is producing only one product.Output and price data for a three-year period are as follows.Answer the question on the basis of these data. $\begin{array}{c}\begin{array}{c}\\\underline{\text { Year }} \\1 \\2 \\3\end{array}\begin{array}{c}\text { Units of}\\\underline{\text {Output}}\\20\\25\\30\end{array}\begin{array}{c}\text {Price Per}\\\underline{\text {Unit}}\\ \$ 4 \\4\\6 \end{array}\end{array}$
Refer to the data.If year 2 is chosen as the base year,real GDP for year 1 is:

A) $25.
B) $100.
C) $20.
D) $80.