Choose the One Alternative That Best Completes the Statement or Answers

Choose the one alternative that best completes the statement or answers the question.
-Economists use what is called a Leffer curve to predict the government revenue for tax rates from $0 \%$ to $100 \%$ . Economists agree that the end points of the curve generate 0 revenue, but disagree on the tax rate that produces $t$ maximum revenue. Suppose an economist produces this rational function
$R ( x ) = \frac { 10 x ( 100 - x ) } { 25 + x }$ , where $R$ is revenue in millions at a tax rate of $x$ percent. Use a graphing calculator to graph the function. What tax rate produces the maximum revenue? What is the maximum revenue?

A) $38.4 \% ; \$ 383$ million
B) $27.0 \% ; \$ 379$ million
C) $28.8 \% ; \$ 272$ million
D) $30.9 \%$ ; $\$ 382$ million