The Accompanying Table Is the Before-Tax Consumption Schedule for a

Multiple Choice

$$\begin{array} { | c | c | } \hline \text { Gross Domestic Product (GDP) } & \text { Consumption (C) } \\\hline \$ 0 & \$ 40 \\\hline 100 & 120 \\\hline 200 & 200 \\\hline 300 & 280 \\\hline 400 & 360 \\\hline\end{array}$$ The accompanying table is the before-tax consumption schedule for a closed economy. If a lump-sum tax (the same tax amount at each level of GDP) of $40 is imposed in this economy, the tax system

A) is regressive.
B) is proportional.
C) is progressive.
D) may be either proportional or progressive.