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

Multiple Choice

Fran runs a doughnut shop in a tiny 3-person town.Fran's rational consumers have the following demand schedules: $$\begin{array} { | l | l | l | l | } \hline \text { Price } & \text { Art } & \text { Betty } & \text { Cal } \\\hline 10 \text { cents } & 10 & 4 & 6 \\\hline 25 \text { cents } & 9 & 2 & 5 \\\hline 35 \text { cents } & 7 & 1 & 5 \\\hline 50 \text { cents } & 5 & 0 & 4 \\\hline\end{array}$$
Market demand for doughnuts when the price is 50 cents is

A) 31 doughnuts.
B) 20 doughnuts.
C) 9 doughnuts.
D) 13 doughnuts.