Fran Runs a Doughnut Shop in a Tiny 3-Person Town

Multiple Choice

Fran runs a doughnut shop in a tiny 3-person town. The table below shows the quantity demand by the three townspeople at various prices. $$\begin{array} { | c | c | c | c | } \hline \begin{array} { c } \text { Price Per } \\\text { Doughnut }\end{array} & \begin{array} { c } \text { Quantity } \\\text { Demanded } \\\text { by Al }\end{array} & \begin{array} { c } \text { Quantity } \\\text { Demanded } \\\text { by Betty }\end{array} & \begin{array} { c } \text { Quantity } \\\text { Demanded by } \\\text { Carol }\end{array} \\\hline 10 \text { cents } & 10 & 4 & 6 \\\hline 25 \text { cents } & 9 & 2 & 5 \\\hline 35 \text { cents } & 7 & 1 & 5 \\\hline 50 \text { cents } & 5 & 0 & 4 \\\hline\end{array}$$ When the price of a doughnut is 50 cents, what is the market demand for doughnuts?

A) 31 doughnuts
B) 20 doughnuts
C) 9 doughnuts
D) 5 doughnuts