In her new job in the financial analysis department at Logan Company, Carolyn Bertozzi is being bombarded with unfamiliar terminology. For example, she is frequently hearing the terms $$fixed costs,$$variable costs,$$ and $$relevant range.$$ Carolyn knows that RENT is a good example of a fixed cost. How can Carolyn expect the cost of RENT to behave?

a$.$ Increasing in total over the relevant range

b$.$ Constant per unit over the relevant range

c$.$ Decreasing in total over the relevant range

d$.$ Constant in total over the relevant range