Find the Cost Function for the Marginal Cost $\frac { d C } { d x } = \frac { 1 } { 40 } x ^ { 2 } + 90$

Multiple Choice

Find the cost function for the marginal cost $\frac { d C } { d x } = \frac { 1 } { 40 } x ^ { 2 } + 90$ and fixed cost of $\$ 2000$ (for x = 0) .

A) $C ( x ) = \frac { 1 } { 80 } x ^ { 3 } + 90 x + 2000$
B) $C ( x ) = \frac { 1 } { 120 } x ^ { 3 } + 2000 x + 90$
C) $C ( x ) = \frac { 1 } { 120 } x ^ { 3 } + 90 x + 2000$
D) $C ( x ) = \frac { 1 } { 80 } x ^ { 4 } + 2000 x + 90$
E) $C ( x ) = \frac { 1 } { 120 } x ^ { 4 } + 90 x + 2000$