Solve the Problem $x$ Pretzels Is Given by the Function $P ( x ) = - 0.004 x ^ { 2 } + 2.4 x - 200$

Multiple Choice

Solve the problem.
-The profit that the vendor makes per day by selling $x$ pretzels is given by the function $P ( x ) = - 0.004 x ^ { 2 } + 2.4 x - 200$ . Find the number of pretzels that must be sold to maximize profit.

A) 300 pretzels
B) 600 pretzels
C) $1.2$ pretzels
D) 160 pretzels