Write a Cost Function for the Problem $\$ 90 ; 60$

Multiple Choice

Write a cost function for the problem. Assume that the relationship is linear.
-Marginal cost, $\$ 90 ; 60$ items cost $\$ 5800$ to produce

A) $C(x) =7 x+400$
B) $C(x) =90 x+400$
C) $C(x) =90 x+5800$
D) $C(x) =7 x+5800$