Choose the correct description of variable and fixed costs.

A. A variable cost changes in total in proportion to changes in the related level of total activity or volume,

such as a sales commission that is a percentage of each sales revenue dollar. A fixed cost remains

unchanged in total for a given time period, despite wide changes in the related level of total activity or

volume, such as a fixed annual leasing cost of a machine.

B. A variable cost is considered to be a unit cost, such as the per-attendee-cost of hiring a musical group

to perform at an event. A fixed cost is considered to be a total cost, such as the total fee paid to the musical

group for performing at the event.

C. A variable cost is related to a particular cost object and can be traced to it in an economically feasible

way, such as the cost of steel in the manufacturing of a luxury car. A fixed cost is related to a particular

cost object but cannot be traced to it in an economically feasible way, such as the salary of a plant manager

who oversees production of many different types of luxury cars produced at the same plant.

D. All of the above.