The change in total cost per unit of change in output is known as by which name

Option 1: Average Cost -> This is total cost divided by quantity (TC/Q), not the rate of change.

Option 2: Variable Cost -> Costs that vary with output level, but not defined as change in TC per unit change in output.

Option 3: Fixed Cost -> Costs that remain constant regardless of output level.

Option 4: Short Run Marginal Cost -> This is the change in total cost when output changes by one unit.

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Hence, Option 4: Short Run Marginal Cost -> Marginal Cost (MC) is mathematically defined as MC = ΔTC/ΔQ, which represents the change in total cost (ΔTC) per unit change in output (ΔQ). In the short run, when at least one factor is fixed, this is called Short Run Marginal Cost. It helps firms determine the additional cost of producing one more unit of output. -> correct