The Revenue R (In Dollars) Generated by the Sale of X

The revenue R (in dollars) generated by the sale of x units of a patio furniture set is given by $( x - 116 ) ^ { 2 } = - \frac { 4 } { 5 } ( R - 16,820 )$ .Approximate the number of sales that will maximize revenue.

A) $R = 116 x - \frac { 5 } { 4 } x ^ { 2 }$ The revenue is maximum when $x = 116$ units.
B) $R = 116 x + \frac { 5 } { 4 } x ^ { 2 }$ The revenue is maximum when $x = 16,820$ units.
C) $R = 290 x + \frac { 5 } { 4 } x ^ { 2 }$ The revenue is maximum when $x = 16,820$ units.
D) $R = 290 x - \frac { 5 } { 4 } x ^ { 2 }$ The revenue is maximum when $x = 116$ units.
E) $R = 290 x + \frac { 5 } { 4 } x ^ { 2 }$ The revenue is maximum when $x = 290$ units.