For each of the items below, type the letter whether it should be considered a differential cost, an opportunity cost, a sunk cost on none of the choices in the decision to replace the old X-ray machine with a new machine. Northwest Hospital is a full-service hospital that provides everything from major surgery and emergency room to outpatient clinic. The hospital's Radiology Department is considering replacing an old inefficient X-ray machine with a state-of-the-art digital X-ray. The new machine would provide higher quality X-rays in less time and at a lower cost per X-ray. It would also require less power and would use a color laser printer to produce easily readable X-ray images. Instead of investing the funds in the new X-ray machine, the Laboratory Department is lobbying the hospital's management to buy a new DNA analyzer.