Solve the Problem $M(x)$ , in Millions, in a Certain Area Depends on the Millions

Multiple Choice

Solve the problem.
-The number of mosquitoes $M(x)$ , in millions, in a certain area depends on the June rainfall $x$ , in inches: $\mathrm{M}(\mathrm{x}) =4 \mathrm{x}-\mathrm{x}^{2}$ . What rainfall produces the maximum number of mosquitoes?

A) 16 inches
B) 4 inches
C) 0 inches
D) 2 inches