As production increases, variable costs per unit

A) stay the same
B) increase
C) decrease
D) either increase or decrease, depending on the fixed costs

Variable costs per unit stay the same as production increases. These costs vary directly with the level of production, but on a per-unit basis, they remain constant. Fixed costs, on the other hand, are spread over more units with increased production, affecting the per-unit cost, but this does not apply to variable costs.