The stakeholder engagement plan is the document that translates insights from stakeholder analysis into specific engagement activities. It specifies how stakeholders will be engaged, when, by whom, and with what tools. ACMP defines it as a core output of stakeholder analysis. Resource plans (A) address capacity, while risk charters (C) and sustainability (D) focus on later stages. Thus, the correct plan is stakeholder engagement plan.

(Reference: ACMP Standard, Process Group 3 -- Stakeholder Engagement Plan; Output: Activities linked directly to stakeholder analysis results.)