From this simple linear model, it's clear that Donald perceives the cost behavior as entirely variable with no fixed cost component. His understanding of the costs is as follows: Variable Cost for Each Pizza: Donald assigns a higher variable cost of $6.00 per pizza, which suggests he believes that every element of the cost to make a pizza, including what might conventionally be considered fixed overhead costs, is variable and directly tied to the number of pizzas produced. No Separation of Fixed Costs: Unlike Helen, Donald doesn't separate any fixed overhead (MOH) from the variable costs. This implies he does not identify any part of the costs as staying constant regardless of the number of pizzas made. Donald's model suggests that he believes all the costs scale directly with the number of units. This could mean that he either does not account for any fixed costs in his analysis, or he views all costs, including those that are typically fixed, as variable on a per unit basis for each pizza. Ultimately, Donald's model suggests a single cost behavior: variable, with a total cost that changes directly in proportion to the number of units produced, without a breakpoint where a fixed