When average total cost is declining,then

A) marginal cost must be less than average total cost.
B) marginal cost must be greater than average total cost.
C) average total cost must be greater than average fixed cost.
D) average variable cost must be declining.

Marginal Cost

The cost added by producing one additional unit of a product or service, a crucial concept for making economic decisions.

Average Total Cost

The total cost divided by the quantity produced, indicative of the cost per unit of output.

Average Fixed Cost

Fixed cost divided by output.