Ratzlaff Company has a current production level of 20,000 units per month. Unit costs at this level are: Current monthly sales are 18,000 units @ \$3.00/unit. Jim Company has contacted Ratzlaff Company about purchasing 1,500 units at $2.00 each. Current sales would not be affected by the one-time-only special order, and variable marketing costs would not be incurred on the special order. However, a $400 engraving tool would have to be purchased. 7. What is Ratzlaff Company's change in net income if the special order is accepted? a. $1,400 increase in net income b. $1,200 increase in net income c. $1,800 increase in net income d. $1,600 increase in net income