(Table) Based on the Table, What Is the Shape of the Demand

(Table) Based on the table, what is the shape of the demand curve that faces John's Tricycle Company?
$\begin{array}{|c|c|c|}\hline \text { Output } & \begin{array}{c}\text { Marginal } \\\text { Cost }\end{array} & \begin{array}{c}\text { Total } \\\text { Revenue }\end{array} \\\hline 5 & 1,200 & 7,500 \\\hline 6 & 1,300 & 9,000 \\\hline 7 & 1,400 & 10,500 \\\hline 8 & 1,500 & 12,000 \\\hline 9 & 1,600 & 13,500 \\\hline\end{array}$

A) downward sloping
B) horizontal
C) vertical
D) upward sloping