Assume a plant manager is interested in analyzing the total cost (per month) of a raw material used in the production process. The relevant cost driver for this cost is number of units produced (per month). Assume the supplier of the raw material offers a bulk (volume) discount. In the related cost graph, the total cost line would be:

 a.  non-linear

b.  linear starting at the origin (where X=0 and Y=0)

c.  linear starting at a point other than the origin.