which of the following is the correct way to calculate total cost?

The correct way to calculate total cost is to add the fixed cost and variable cost together. Fixed costs are expenses that do not change with the amount of output, such as rent or salaries, while variable costs are expenses that increase or decrease as the amount of output changes, such as raw materials or labor. Adding the fixed cost to the variable cost gives the total cost of producing a certain amount of output. This is because fixed costs are already incurred and do not change based on the level of output, while variable costs increase or decrease as the level of output changes. Therefore, the correct option is the one that suggests "Addition of fixed cost to variable cost."