Answer:
c. Division 1 should continue to do business with Division 2 because Division 1's variable cost per part is only $18.
Step-by-step explanation:
Since the variable cost per part is only $18 and Division 1 sells to Division 2 at $25, it is in the company's overall interest that business should continue between the two divisions.
The cost of getting the part from outside is $26. This will incur more cost to the company and create excess capacity for Division 1.
Fixed costs are not relevant in making a decision of this nature. The costs would be incurred irrespective of the decision made. They are therefore irrelevant. The relevant cost is the variable cost of $18 per unit. It should be the focus of the decision, including the possibility of excess capacity for Division 1.