A laboratory is launching a new product planned for eight iterations with a fixed release date. At the start of the second iteration, the project manager discovers a significant regulatory feature is missing from the backlog. What should the project manager do?

The product owner is responsible for managing the product backlog, which includes adding, refining, and prioritizing items. Since the regulatory feature is critical and missing, the product owner must add it to the backlog for consideration. Inviting stakeholders to discuss the impact is a subsequent step after the feature is formally in the backlog and its priority can be evaluated. Estimating cost and requesting an extension are premature actions; the first step is to get the feature into the backlog for proper assessment and prioritization. Increasing team capacity without first evaluating the feature's priority and impact on existing work is not the initial appropriate response.