Table 51 -Refer to Table 5

Table 5.1
$$\begin{array}{l}\text { Table } 5.1\\\begin{array} { | c | c | c | } \hline \begin{array} { l } \text { Aggregate Demand (quantity } \\\text { demanded in billions of dollars) }\end{array} & \begin{array} { l } \text { Price Level } \\( \$ ) \end{array} & \begin{array} { l } \text { Aggregate Supply (quantity supplied in billions of } \\\text { dollars) }\end{array} \\\hline 100 & 150 & 1,200 \\\hline 200 & 125 & 1,000 \\\hline 400 & 100 & 800 \\\hline 600 & 75 & 600 \\\hline 800 & 50 & 400 \\\hline 1,000 & 25 & 200 \\\hline\end{array}\end{array}$$
-Refer to Table 5.1, which shows an aggregate demand schedule and an aggregate supply schedule. What is aggregate supply at a price level of $75?

A) $200 billion dollars
B) $400 billion dollars
C) $600 billion dollars
D) $800 billion dollars
E) $1,000 billion dollars