Option 1: Total Variable Cost and Total Cost increase. -> When a firm increases output, it must use more variable inputs (labor, raw materials, etc.). This causes Total Variable Cost (TVC) to rise. Since Total Cost (TC) = Total Fixed Cost (TFC) + Total Variable Cost (TVC), and fixed costs remain constant while variable costs increase, the Total Cost must also increase. This represents the fundamental relationship between production levels and costs in the short run. -> correct