Question Content AreaDiamond, Inc.$\text{'}$s most recent contribution margin income statement shows the following:

Line Item Description Amount

Sales @ $$10$ per unit $$160,000$

Less: Variable expenses $(120,000)$

Contribution margin $ $40,000$

Less: Fixed expenses $(50,000)$

Operating income $($loss$)$ $ $(10,000)$

If Diamond, Inc's advertising costs increased by $$5,000,$ by how much would sales have to increase for the company to achieve an operating income of $$4,000?$

a$.$ $$18,000$

b$.$ $$42,000$

c$.$ $$76,000$

d$.$ $$56,000$