Solve the Problem $C D$ the Cost in Dollars to Produce A a New

Multiple Choice

Solve the problem.
-A rock group is producing a new $C D$ . The cost in dollars to produce a $C D$ is given by $C(x, y) =21,500+x^{2}-140 x+3 y^{2}-84 y$ , where $x$ is the number of man hours of work required and $y$ is the number of hours of studio time required. Find the minimum cost.

A) $\$ 16,612$
B) $\$ 18,442$
C) $\$ 15,792$
D) $\$ 16,012$