A legislative change is an external constraint that can create urgent compliance needs. However, once a sprint starts, scope changes should be minimized to protect focus and predictability. The correct action is to update the product backlog and prioritize the change for the next iteration (D), ensuring it is visible, sized, and ordered appropriately by the product owner. This respects agile cadence while enabling rapid response via reprioritization. Immediately changing the sprint backlog (A or B) is generally discouraged unless the team and product owner agree the change is critical enough to cancel or renegotiate the sprint; the question does not indicate such a decision. Advising the team to add it to acceptance criteria (C) is risky because it changes the committed work after planning and may introduce unestimated effort, jeopardizing sprint goals. By placing the change into the product backlog as high priority, the project lead ensures transparent governance, proper estimation, and planned implementation, balancing compliance urgency with disciplined iteration management.