This Table Shows Demand for Shoes in a 3 Consumer

This table shows demand for shoes in a 3 consumer market: $$\begin{array} { | l | l | l | l | } \hline \begin{array} { l } \text { When the price } \\\text { of shoes is }\end{array} & \begin{array} { l } \text { Pat buys this } \\\text { many: }\end{array} & \begin{array} { l } \text { Leigh buys this } \\\text { many: }\end{array} & \begin{array} { l } \text { and Chris buys } \\\text { this many: }\end{array} \\\hline \$ 100 \text { a pair } & \text { none } & 1 \text { pair } & \text { none } \\\hline \$ 75 \text { a pair } & \text { none } & 3 \text { pairs } & 1 \text { pair } \\\hline \$ 50 \text { a pair } & 1 \text { pair } & 7 \text { pairs } & 3 \text { pairs } \\\hline \$ 30 \text { a pair } & 2 \text { pairs } & 10 \text { pairs } & 5 \text { pairs } \\\hline\end{array}$$
What is the market demand for shoes when the price is $50 per pair?

A) 7 Pairs of shoes.
B) 11 Pairs of shoes.
C) 15 Pairs of shoes.
D) It will depend on the supply at $50.