A project is 70% complete when the sponsor requests an additional deliverable. What should the project manager do first?

The project manager's first step should be to determine the impact of the requested change. This involves assessing how the new deliverable affects the project's scope, schedule, cost, quality, resources, risks, and other aspects. Understanding the full implications is crucial before any further action. Negotiating alternatives or rejecting the request outright without understanding the impact is premature. Submitting to the Change Control Board (CCB) is a later step, after the impact analysis is complete and documented, allowing the CCB to make an informed decision based on the potential consequences.