1. The problem asks for the most important factor in a sell-or-process-further decision. 2. In managerial accounting, a sell-or-process-further decision involves deciding whether to sell a product at an intermediate stage or process it further to sell at a later stage. 3. The key formula to consider is the incremental analysis: $$\text{Incremental Profit} = \text{Additional Revenue} - \text{Additional Processing Cost}$$ 4. Joint costs are sunk costs incurred before the split-off point and should not affect the decision. 5. Units produced and fixed overhead are not the primary factors because the decision focuses on incremental costs and revenues. 6. Therefore, the most important factor is comparing the additional revenue from further processing to the additional processing cost. 7. If additional revenue exceeds additional processing cost, it is beneficial to process further; otherwise, sell at the split-off point. Final answer: Additional revenue vs additional processing cost