Solve the Problem $y$ , to Build an Oil Platform Of $x$

Multiple Choice

Solve the problem.
-Suppose the cost per ton, $y$ , to build an oil platform of $x$ thousand tons is approximated by $f ( x ) = \frac { 312,500 } { x + 625 }$ . What is the cost per ton for $x = 400$ ?

A) $\$ 304.88$
B) $\$ 121,951.22$
C) $\$ 156.25$
D) $\$ 200,000.00$