Cathy Company is considering whether to sell Retox at the split-off point or subject it to further processing and produce a more refined product known as Retox-F. Consider the following items: I. The selling price of Retox-F. II. The direct material and direct labor costs incurred up to the split-off point. III. The additional (separable) cost of producing Retox-F. IV. The selling price of Retox. Which of the above items are relevant to Cathy's decision to process Retox into Retox-F? I, II, III, and IV I and III I. II, and III I. III, and IV I and II