Answer: D. Keep Customer Z because eliminating this company would have the effect of decreasing company profit by $580,000.
Step-by-step explanation:
If Customer Z is eliminated, the company losses profit of $580,000. This is not very ideal because should this happen the entire $1,000,000 in allocated fixed costs will be shifted to Customer X because it is stated that total fixed costs remain the same regardless.
As it stands the company is making a net profit of,
=( 600,000 - (1,000,000*40%) ) + ( 580,000 - (1,000,000 * 60%)
= 200,000 + (-20,000)
= $180,000
If they eliminate Customer Z, that profit goes to a loss of,
= 600,000 - 1,000,000
= -$400,000