Solve the Problem $x$ Thousand Units of a Certain Product Is Given By

Solve the problem.
-The cost of producing $x$ thousand units of a certain product is given by $C=-5.8 x^{2}+4807 x+200,000$ , for $x \leq 150$ . Write a rational expression that gives the average cost per unit when $x$ thousand are produced. Then find the average cost per unit when 30,000 units are produced.

A) $\frac{-5.8 x^{2}+4807 x+200,000}{1000 x} ; \$ 162.53$
B) $\frac{-5.8 x^{2}+4807 x+200,000}{1000 x} ; \$ 11.30$
C) $\frac{-5.8 x^{2}+4807 x+200,000}{x} ; \$ 11.30$
D) $\frac{-5.8 x^{2}+4807 x+200,000}{x} ; \$ 11,299.67$