A computer manufacturer is assessing the total cost of outsourcing the manufacture of peripheral components (e.g., keyboards and mouses) to their current supplier. Which of the following costs should not be included in calculating total cost of ownership? I. Discounts received from the supplier due to bulk purchases. II. Costs of having back-up suppliers due to unforeseen increases in customer orders. III. Costs of sales returns due to malfunctioning keyboards. IV. Costs of collaborating with supplier on research and development projects to develop sustainable keyboards.

a.I only

b.II, III and IV only

c.I, II, and III only

d.II only

e.III only