Billings Company Has the Following Costs When Producing 100,000 Units $\quad \$ 600,000$

Billings Company has the following costs when producing 100,000 units: Variable costs $\quad \$ 600,000$
Fixed costs $\quad 900,000$ An outside supplier has offered to make the item at $4.50 a unit. If the decision is made to purchase the item outside, current production facilities could be leased to another company for $165,000. The net increase (decrease) in the net income of accepting the supplier's offer is

A) $285,000.
B) $315,000.
C) $(15,000) .
D) $840,000.