The Following Is Addison Corporation's Contribution Format Income Statement for Last

The following is Addison Corporation's contribution format income statement for last month:

$\begin{array} { | l | r | } \hline \text { Sales } & \$ 1,000,000 \\\hline \text { Less: variable expenses } & \underline { 700,000 } \\\hline \text { Contribution margin } & 300,000 \\\hline \text { Less: fixed expenses } & \underline { 180,000 } \\\hline \text { Operating income } & \$ 120,000 \\\hline\end{array}$ The company has no beginning or ending inventories. A total of 20,000 units were produced and sold last month.

-If sales increase by 100 units,by how much should operating income increase?

A) $400.
B) $4,800.
C) $1,500.
D) $2,500.