A cost accountant is attempting to find a linear model that describes the cost of producing a firms product. She has the following data: Units 5000 6000 8000 7000 Cost $110,000 $135,000 $155,000 $180,000 Find the linear model by using linear regression analysis which best describes cost as a function of the number of units produced. Select one: O a. C(x) 28x18000 O b. C(x) = 18x + 28000 Oc. C(x) 18x d, C(x) = 150000