Which of the following could be a reason why an assembly shows a "0" cost after a cost rollup?

The assembly showing a "0" cost after a cost rollup can occur if the assembly item is marked as Perpetual Average costed. In a Perpetual Average costing system, the costs of components are averaged over time, and if the underlying components or child components do not have associated costs, the assembly will ultimately reflect a cost of zero after the rollup process.

In this context, each assembly item typically derives its total cost from its child components. If these child components are uncosted or not assigned any value, the assembly will inherit that zero cost in the rollup process. Although other options may present scenarios influencing costs, they do not directly lead to a zero cost as definitively as having uncosted child components in a Perpetual Average costing scenario.