Find an Equation for the Rational Function Graph $f ( x )$

Multiple Choice

Find an equation for the rational function graph.
-Suppose the cost per ton, $f ( x )$ , to build an oil platform of $x$ thousand tons is approximated by $f ( x ) = \frac { 62,500 } { x + 125 }$ . What is the cost per ton for $x = 30$ ?

A) $\$ 403.23$
B) $\$ 2083.33$
C) $\$ 1958.33$
D) $\$ 16.67$