Answer:
The correct answer is step-wise cost.
Step-by-step explanation:
Step-wise cost is a cost type that remains fixed over a relevant range of output but changes in a step when output goes beyond that level of output.
The change noticed could be either be an increase or decrease depending on the nature of the cost itself.
In this instance,the supervisor's salary initially remains fixed regardless of the level output if original shift remains the same, but changes by additional salary of a new supervisor when the new shift commences.