Solve the Problem $x$ Of the Rectangle $A$ ?
A) $\mathrm { A } ( \mathrm { x } ) = - \mathrm { x } ^ { 2 } + 1,600 \mathrm { x } ; \quad \{ \mathrm { x } \mid 0 < \mathrm { x } < 1,600 \}$

Multiple Choice

Solve the problem.
-A farmer has 1,600 yards of fencing to enclose a rectangular garden. Express the area A of the rectangle as a function of the width $x$ of the rectangle. What is the domain of $A$ ?

A) $\mathrm { A } ( \mathrm { x } ) = - \mathrm { x } ^ { 2 } + 1,600 \mathrm { x } ; \quad \{ \mathrm { x } \mid 0 < \mathrm { x } < 1,600 \}$
B) $\mathrm { A } ( \mathrm { x } ) = - \mathrm { x } ^ { 2 } + 800 \mathrm { x } ; \{ \mathrm { x } \mid 0 < \mathrm { x } < 1,600 \}$
C) $\mathrm { A } ( \mathrm { x } ) = - \mathrm { x } ^ { 2 } + 800 \mathrm { x } ; \{ \mathrm { x } \mid 0 < \mathrm { x } < 800 \}$
D) $A ( x ) = x ^ { 2 } + 800 x ; \{ x \mid 0 < x < 800 \}$