Final answer:
After evaluating the costs and sales price, it is concluded that Oak Company should sell finished bookcases since the net income per unit increases by $2, making option C the correct answer.
Step-by-step explanation:
The question at hand requires an evaluation of whether Oak Company should sell unfinished bookcases or sell them finished by analyzing the impact on net income per unit. To determine this, we need to compare the increase in sales price to the increase in variable costs when finishing the bookcases. Currently, the unfinished bookcases are sold for $62, with variable costs of $36 and fixed costs of $10, making the profit per unit $16. If the bookcases are finished, the selling price will be $70, and the new variable costs will be $42 (original $36 plus finishing cost of $6) while fixed costs remain at $10; this results in a profit per unit of $18. Thus, the net income per unit increases by $2 when finishing the bookcases.
Therefore, the correct option is C) sell finished bookcases because the net income per unit increases $2.