The Number of Wrenches That Can Be Produced at a Given

Multiple Choice

The number of wrenches that can be produced at a given price can be predicted by the formula $s = \sqrt { 65 x }$ , where $s$ is the supply (in thousands) and $X$ is the price (in dollars) . If the demand $d$ for the wrenches can be predicted by the formula $d = \sqrt { 324 - 4 x ^ { 2 } }$ , find the equilibrium price.

A) $6
B) $5
C) $4
D) None of the above