A finance team is forecasting the cost of a customer support assistant built on a hosted foundation model. They plan to budget per active user per month. What should they be told about how the cost actually behaves?

• ACost is billed per user session, so the per user assumption is broadly correct.
• BCost is fixed once the model is deployed, because inference does not consume metered resources.
• CCost depends on the number of parameters in the model rather than on usage.
• DCost is billed per token of input and output, so it scales with conversation length and document size rather than with user count.