Cost-volume-profit analysis is based on necessary assumptions. which of the following is not one of these assumptions? select one:

a. costs can be classified as variable or fixed.
b. relevant range includes all possible levels of activity that a company might experience.
c. sales price and variable costs per unit of output remain constant as volume changes.
d. a constant sales mix in a multiproduct company.
e. total fixed costs are held constant.

Kubin company’s relevant range of production is 18,000 to 22,000 units. when it produces and sells 20,000 units, its average costs per unit are as follows: average cost per unit direct materials $ 7.00 direct labor $ 4.00 variable manufacturing overhead $ 1.50 fixed manufacturing overhead $ 5.00 fixed selling expense $ 3.50 fixed administrative expense $ 2.50 sales commissions $ 1.00 variable administrative expense $ 0.50 required: 1. for financial accounting purposes, what is the total amount of product costs incurred to make 20,000 units? 2. for financial accounting purposes, what is the total amount of period costs incurred to sell 20,000 units? 3. for financial accounting purposes, what is the total amount of product costs incurred to make 22,000 units? 4. for financial accounting purposes, what is the total amount of period costs incurred to sell 18,000 units?