The Demand Function in the Accompanying Table Is Q_X^d =

Multiple Choice

The demand function in the accompanying table is Q_X^d = 100 ? 2P_X.Based on this information,when Q_X = 80,the price,P_X (point A) ,is:
$\begin{array}{cccc}\begin{array}{c}\text { Good X } \\\left(\mathbf{P}_{\mathbf{x}) }\right.\end{array} & \begin{array}{c}\text { Quantity } \\\text { of GoodX } \\\left(\mathbf{Q}_{\mathbf{X}}\right) \end{array} & \begin{array}{c}\text { Own } \\\text { Price } \\\text { Elasticity }\end{array} & \begin{array}{c}\text { Total } \\\text { Revenue }\end{array} \\5 & 100 & 0.00 & 0 \\\text { A } & 90 & -0.11 & 450 \\15 & 80 & -0.25 & 800 \\20 & 70 & -0.43 & 1050 \\25 & 60 & -0.67 & 1200 \\30 & 50 & \mathbf{C} & 1250 \\35 & \mathbf{B} & -1.50 & 1200 \\40 & 30 & -2.33 & 1050 \\45 & 20 & -4.00 & \mathbf{D} \\50 & 10 & -9.00 & 450 \\50 & 0 & -\infty & 0\end{array}$

A) $5.
B) $10.
C) $15.
D) $20.